Essay: Reflecting on the Legacy of James Dewey Watson (6 April 1928 – 6 November 2025) 🧬

Essay: Reflecting on the Legacy of James Dewey Watson (6 April 1928 – 6 November 2025) 🧬

Author: Adisha Kariyawasam, BSc (Hons), MSc, PGCE, AFHEA, MBCS — 

Date published: 16th November 2025

James Watson (1928–2025) pictured alongside a chalkboard illustration of the DNA double helix and base-pairing (CNN, 2025).

Introduction

The passing of James Dewey Watson (6 April 1928 – 6 November 2025) marks the end of one of the most influential, controversial and paradoxical chapters in modern scientific history. As co-discoverer of the double-helix structure of DNA, Watson helped unlock the biochemical foundation of life, laying the groundwork for molecular biology, biotechnology, genetics and medical research as we know them today (Crick, 1988; Franklin & Gosling, 1953; Watson & Crick, 1953).

Yet his legacy is also overshadowed by decades of widely criticised remarks about race, gender, sexuality and appearance—statements inconsistent with scientific evidence and incompatible with contemporary ethical standards (Borger, 2007; Yong, 2019).

This essay reflects on the significance and complexity of Watson’s legacy, while acknowledging the profound role that the story of the double-helix discovery played in shaping my own academic journey into Molecular Biophysics at the University of Leeds.

The Double Helix: A Discovery That Transformed Biology

Watson’s scientific rise began in the early 1950s at Cambridge, where he collaborated with Francis Crick to solve what was then considered one of the most profound mysteries in science: the molecular structure of DNA. Their breakthrough, published in Nature in 1953, proposed the now-iconic double-helix model, in which complementary base-pairing suggested a natural mechanism for DNA replication (Watson & Crick, 1953).

Although Watson and Crick’s conceptual insight was extraordinary, their work depended critically on the X-ray diffraction photographs and analysis produced by Rosalind Franklin and Raymond Gosling at King’s College London (Franklin & Gosling, 1953). Franklin’s Photo 51, shown to Watson without her permission, became a turning point in the race to decode life’s molecular structure (The Economist, 2025).

Their joint discovery earned Watson, Crick and Wilkins the 1962 Nobel Prize in Physiology or Medicine, marking one of the great scientific milestones of the 20th century (Crick, 1988).

Leadership, Institutions, and the Genomic Revolution

Watson’s scientific influence continued long after the double-helix discovery. He revitalised the Cold Spring Harbor Laboratory (CSHL), transforming it from a declining facility into a global centre for molecular genetics and cancer research (Watson, 2007).

At Harvard University, he founded and led the molecular-biology department, helping shape academic pathways and research disciplines for generations of scientists.

Most notably, Watson served as the first director of the Human Genome Project, one of the most ambitious scientific undertakings in history (NHGRI, 2003). He later became the second person to have his entire genome sequenced and published openly, reinforcing his belief that genetic information should not be patented but shared freely for the benefit of humanity.

These achievements contributed to enormous advances in medicine, genomics, biotechnology, diagnostics and personalised health.

Controversies and Ethical Concerns

Despite his scientific brilliance, Watson’s later career was marred by numerous public remarks widely condemned as discriminatory, unscientific and deeply harmful. His 2007 comments on race and intelligence (Borger, 2007), reiterated again in 2019 (Yong, 2019), were met with global outrage and resulted in the removal of all remaining honorary titles at Cold Spring Harbor Laboratory (CSHL, 2019).

His comments on women, LGBTQ+ people and body weight further fuelled criticism and led to painful debates about the responsibilities of scientific leaders in public life. Institutions, colleagues and scholars increasingly distanced themselves from Watson, emphasising that excellence in science must be accompanied by respect, equity and ethical integrity.

Watson’s 2014 decision to sell his Nobel Prize medal for $4.8 million, claiming he felt ostracised, became a symbolic moment in his personal and institutional decline (Sample, 2014). In an unexpected act of generosity, the anonymous buyer returned the medal to him immediately.

A Personal Reflection: Inspiration for My Academic Pathway

Despite the controversies of Watson’s later years, the story of the double-helix discovery — the race, the science, the elegance of the structure, and the transformative impact on medicine — was a defining inspiration in my own life.

It was this narrative that motivated me to pursue a BSc (Hons) in Molecular Biophysics at the University of Leeds, where the interplay of physics, chemistry and biology could be explored through the lens of structural biology, spectroscopy, molecular modelling and biophysical mechanisms.

The discovery of DNA’s structure was one of the first scientific stories that made me appreciate how curiosity, insight and interdisciplinary thinking could change the world. This inspiration formed the foundation of my continuing academic and professional journey — spanning molecular science, technology, data analytics, teaching, wellbeing and leadership.

Conclusion: Holding Two Truths Together

James Watson’s legacy is neither wholly heroic nor wholly condemnable. It is deeply and unavoidably dual:

A scientist of extraordinary insight who helped uncover the molecular basis of life.

A public figure whose later statements increasingly contradicted scientific evidence and human dignity.

As we reflect on his passing, we must honour the historic significance of the double helix while also learning from the ethical failures that overshadowed his later years. His life serves as a reminder that the power of scientific discovery must always be matched with humility, responsibility, and respect for all members of humanity.

References

Borger, J. (2007) ‘Nobel scientist James Watson condemned for race comments’, The Guardian, 18 October.

Cold Spring Harbor Laboratory (2019) CSHL statement on James D. Watson. Available at: https://www.cshl.edu (Accessed: 15 November 2025).

CNN (2025) ‘James Watson, a renowned molecular biologist and one of the Nobel Prize winners for discovering the structure of DNA, dead at 97’, CNN International, 7 November. Available at: https://edition.cnn.com/2025/11/07/us/james-watson-death (Accessed: 15 November 2025).

Crick, F. (1988) What Mad Pursuit: A Personal View of Scientific Discovery. London: Penguin.

Franklin, R. & Gosling, R. (1953) ‘Molecular configuration in sodium thymonucleate’, Nature, 171(4356), pp. 740–741.

Kolata, G. (2007) ‘DNA pioneer James Watson criticised for remarks’, The New York Times, 18 October.

National Human Genome Research Institute (2003) The Human Genome Project: Fact Sheet. Available at: https://www.genome.gov (Accessed: 15 November 2025).

Sample, I. (2014) ‘James Watson sells Nobel Prize medal’, The Guardian, 4 December.

The Economist (2025) ‘Obituary | The secret of life: James Watson’, The Economist, 6 November.

Watson, J.D. (1968) The Double Helix: A Personal Account of the Discovery of DNA. London: Weidenfeld & Nicolson.

Watson, J.D. (2007) Avoid Boring People: Lessons from a Life in Science. Oxford: Oxford University Press.

Watson, J.D. & Crick, F.H.C. (1953) ‘Molecular structure of nucleic acids: A structure for deoxyribose nucleic acid’, Nature, 171, pp. 737–738.

Yong, E. (2019) ‘James Watson’s racist statements’, The Atlantic, 2 January.

Disclaimer:

The purpose of this essay is to provide a balanced and academically grounded overview of James Watson’s scientific achievements and the controversies surrounding his later life. All discriminatory or scientifically unsupported remarks attributed to Watson are cited for historical accuracy only and are not endorsed in any form. This essay recognises the harm such statements caused and reinforces the principles of equity, inclusion and scientific integrity.

Essay: Cation Binding Sites in Chicken Annexin V – Literature Review

Cation Binding Sites in Chicken Liver Annexin V [CLAV]

A triclinic Annexin V crystal illuminated by an X-ray beam reveals its four α-helical domains and glowing calcium-binding sites. The artwork honours the precision and artistry of 1993 crystallographic studies at the University of Leeds.

Author: Adisha Kariyawasam BSc Molecular Biophysics, MScIT, PGCE (PCET), BCS

Originally written 1992–1993, BSc (Hons) Molecular Biophysics, University of Leeds
Republished and expanded 2025

Preface (2025 Edition)

This literature review was written in 1992–1993, prior to embarking on my final-year dissertation project, during the concluding phase of my BSc (Hons) Molecular Biophysics degree at the University of Leeds. It formed the preparatory groundwork for experimental work undertaken later that academic year within the Department of Biophysics.

At the time, the field of calcium-binding proteins was rapidly expanding. Researchers were discovering how divalent cations such as Ca²⁺ acted not merely as cofactors but as dynamic regulators of cellular communication, membrane fusion, and blood coagulation. This essay reflects the early stages of structural calcium biology that has since evolved into a major interdisciplinary research area, bridging molecular biophysics, physiology, and medical science.

Cation Binding Sites in Chicken Liver Annexin V [CLAV]

Introduction

Calcium ions (Ca²⁺) are essential to life, serving structural, catalytic, and regulatory functions. They stabilise extracellular matrices, act as intracellular messengers, and modulate enzyme activity. In vertebrates, cytosolic Ca²⁺ concentrations are tightly controlled at approximately 10⁻⁷ M, with transient spikes conveying signalling information.

Among the most intriguing Ca²⁺-binding proteins are the Annexins, a family of calcium-dependent phospholipid-binding proteins that play roles in membrane fusion, inflammation control, and anticoagulation.

Calcium Binding in General and in Proteins

In many biomolecules, Ca²⁺ is coordinated by oxygen atoms arranged in a pentagonal bipyramidal geometry with average Ca–O distances of 2.4 Å. Slight displacements of ligands can yield an octahedral coordination, accommodating other divalent cations such as Mg²⁺.

Most calcium-binding proteins exhibit a coordination number of seven, using oxygen atoms from carboxylate side chains (Asp, Glu), carbonyl groups, and water molecules. These binding geometries define the selectivity and flexibility of calcium interactions in biological systems.

Classes of Calcium-Binding Proteins

Three main classes of Ca²⁺-binding proteins can be distinguished:

1. Extracellular enzymes and structural proteins, where calcium enhances thermal stability or protects against proteolysis.

2. Intracellular regulatory proteins, which bind Ca²⁺ reversibly to modulate enzyme activity. These typically feature repeating motifs such as the EF-hand, a helix–loop–helix structure found in calmodulin, troponin C, and parvalbumin.

3. Annexins, a unique family of amphipathic proteins that bind phospholipids in a calcium-dependent manner but lack the EF-hand motif.

The EF-Hand Motif

The EF-hand, named for its E and F helices, consists of a 12-residue loop flanked by α-helices. Side-chain oxygens from residues such as Asp, Ser, and Thr coordinate a single Ca²⁺ ion, while backbone carbonyls contribute additional ligands. The motif usually occurs in pairs related by a pseudo-twofold symmetry axis, forming cooperative Ca²⁺-binding sites.

Although Annexins lack this structure, understanding the EF-hand provides a comparative framework for interpreting their calcium-binding behaviour.

Annexins: Structure and Characteristics

Annexins are acidic, calcium-dependent proteins that bind to negatively charged phospholipid membranes. They share a conserved structural core composed of four homologous domains, each containing five α-helices (A–E).

Their canonical calcium-binding motif is distinct from the EF-hand, typically represented as:
–K–G–X–G–T–(38 residues)–D/E–,
where X can be any amino acid.

Binding occurs predominantly at loop regions between helices, particularly within domains I, II, and IV. Upon calcium binding, the protein undergoes conformational changes that facilitate membrane association.

Chicken Annexin V

The crystal structure of chicken Annexin V (also known as anchorin CII) was solved to 2.54 Å resolution in 1992. The protein, with a molecular weight of 36 kDa and 320 amino acids, exhibits a bowl-shaped configuration with its convex surface exposed to solvent and the concave surface interacting with membranes.

Domains I & IV and II & III form tightly associated pairs, yet can slide relative to one another in the plane of the membrane. Both the N- and C-termini reside within domain IV. The overall molecular dimensions are approximately 64 Å × 40 Å.

Only the loop regions of domains I, II, and IV contain confirmed Ca²⁺-binding sites, primarily coordinated by carboxylate side chains from Asp and Glu residues.

Predicted Lanthanum Binding Sites

In 1990, Robert Huber and colleagues determined the structure of human Annexin V, revealing two additional cation-binding sites when crystals were soaked in lanthanum nitrate. Surprisingly, the crystals initially cracked but reformed within half an hour, suggesting reversible structural accommodation.

Given the high sequence homology (≈ 78 %) between human and chicken Annexin V, it was reasonable to predict analogous lanthanum-binding sites in the avian protein, located between helices A–B and C–D of domain I.

Unlike the canonical calcium-binding sites, these lanthanum positions lacked full coordination shielding, suggesting partial hydration and weaker binding affinity. Nonetheless, they hinted at potential regulatory or allosteric roles for non-physiological cations in crystal packing and structural flexibility.

Proposed Experimental Approach (1993 Project Plan)

The planned experimental work involved soaking trigonal crystals of chicken Annexin V in lanthanum nitrate and collecting X-ray diffraction data using a Xentronics Area Detector. Structural differences would be determined by calculating difference electron-density maps (Fₒ – Fₙ), phased with the native structure.

Each crystal measured only around 0.17 mm in width and had to be graded for optical clarity and absence of twinning before mounting. The manipulation of these fragile crystals demanded exceptional dexterity; in many cases, they were transferred into narrow 0.2mm quartz capillary tubes using a single human eyelash affixed to a matchstick - a traditional crystallographer’s tool of remarkable delicacy.

The resulting diffraction data were expected to reveal lanthanum-binding positions and any local conformational changes. It was hypothesised that crystal cracking and reformation would not permanently disrupt the protein’s tertiary architecture.

Computational Visualisation of 3D Structures (1992–1993 Context)

During the early 1990s, the interpretation of macromolecular structures relied heavily on stereoscopic computer graphics workstations. At the University of Leeds and other leading biophysics centres, crystallographers used Silicon Graphics (SGI) Indigo and Personal IRIS systems, as well as Evans & Sutherland PS300 vector graphics terminals, to visualise and manipulate protein models derived from X-ray diffraction data.

Molecular coordinates, refined using programs such as PROLSQ and X-PLOR, were rendered as wireframe or ribbon representations that could be viewed stereoscopically using polarised glasses or dual-screen mirror systems. These tools allowed researchers to inspect electron-density maps interactively, adjust atomic models in real time, and identify metal-binding geometries with unprecedented precision.

At Leeds, such systems were connected via VAX/VMS and DECstation networks, running early versions of FRODO, O, and TOM molecular modelling software. For many students, these platforms provided their first encounter with immersive molecular visualisation - a transformative experience that turned static diffraction data into tangible, three-dimensional molecular landscapes.

“To visualise a protein structure in three dimensions at that time required both patience and precision - each movement of a carbonyl group was adjusted manually with a trackball or dial box on a Silicon Graphics terminal, viewed through twin polarised displays that brought the molecular world to life.”

Significance of Cation Binding in Annexins

Cation binding in Annexins is crucial for their role in membrane dynamics. Calcium bridges acidic residues to phospholipid head groups, promoting adhesion and curvature stabilisation. This underlies functions such as exocytosis, endocytosis, and anticoagulant activity.

Lanthanum, with its larger ionic radius and higher charge density, serves as an experimental analogue that helps visualise these binding interactions crystalographically.

Such studies not only enhance understanding of Annexin function but also contribute to broader insights into calcium signalling, membrane repair, and protein–lipid interactions.

Conclusion

The study of cation binding in Annexin V highlights how small ions can govern large-scale biological phenomena. The interplay between metal coordination, protein conformation, and membrane interaction exemplifies structural biology’s power to unify chemical and physiological perspectives.

From these early crystallographic investigations emerged principles that now inform modern calcium-signalling biology and the development of biomimetic materials and medical diagnostics.

Afterword (2025 Reflection)

Since 1993, the Annexin family has grown to include over a dozen identified members, each with specific cellular functions ranging from apoptosis to vesicle trafficking. Advances in cryo-electron microscopy, molecular dynamics, and calcium imaging have validated many of the predictions first explored in this essay.

Annexin V is now widely used in medical diagnostics as a marker for early apoptosis through its selective binding to phosphatidylserine—a remarkable translation of biophysical insight into clinical practice.

The questions first posed in this Leeds project continue to resonate in modern structural biology: how do ions, proteins, and membranes coordinate to produce life’s most fundamental movements?

References

• Bewley, M.C., Boustead, C., Walker, J.H., Waller, D.A. and Huber, R. (1992) ‘Crystal structure of chicken Annexin V,’ Unpublished research paper, University of Leeds and Max-Planck Institute.

• Huber, R., et al. (1990) ‘Structure of human Annexin V and identification of lanthanum-binding sites,’ The EMBO Journal, 9(12), pp. 3867–3874.

• Huber, R., et al. (1990) ‘Lanthanum-binding and crystal rearrangement in Annexin V,’ FEBS Letters, 275(1–2), pp. 15–21.

• Huber, R., et al. (1992) ‘Annexin structures and functions,’ Journal of Molecular Biology, 223, pp. 683–704.

• Kretsinger, R.H. (1987) ‘Calcium-binding proteins,’ Cold Spring Harbor Symposia on Quantitative Biology, 52, pp. 499–510.

• Strynadka, N.C.J. and James, M.N.G. (1989) ‘Structural aspects of calcium binding in proteins,’ Annual Review of Biochemistry, 58, pp. 951–980.

• Swain, A.L., Kretsinger, R.H. and Amma, E.L. (1989) ‘Calcium coordination geometries,’ Journal of Biological Chemistry, 264(28), pp. 16620–16628.

• Voet, D. and Voet, J.G. (1990) Biochemistry. New York: Wiley.

• Walker, J.H., et al. (1992) ‘Phospholipid-binding properties of Annexin V,’ Biochemical Society Transactions, 20, pp. 828–833.

Appendix 1 – Glossary of Key Terms

Term	Definition
Annexin	A family of calcium-dependent phospholipid-binding proteins involved in membrane dynamics and signalling.
Cation	A positively charged ion, such as Ca²⁺ or La³⁺, which can form coordinate bonds with proteins.
Coordination Geometry	Spatial arrangement of atoms or ligands around a central metal ion.
EF-Hand	Helix–loop–helix motif common in calcium-binding proteins.
Electron-Density Map	A 3D representation of electron distribution used in crystallography to model atomic positions.
Lanthanum (La³⁺)	A trivalent rare-earth metal used as a calcium analogue in structural studies.
Phospholipid	A lipid containing a phosphate group, forming the bilayer of cell membranes.
Resolution (Ångström)	Measure of clarity in X-ray crystallographic data; 1 Å = 10⁻¹⁰ m.
Xentronics Area Detector	Early electronic imaging detector used to record X-ray diffraction patterns.
X-ray Crystallography	Technique used to determine atomic structures of macromolecules by analysing diffraction patterns from crystals.

Appendix 2 – Short Biographies of Scientists Mentioned (Alphabetical by Surname)

Amma, E.L.

American crystallographer known for co-authoring studies on calcium-binding coordination with Kretsinger and Swain. Her structural analyses provided foundational understanding of protein–ion interactions.

Bewley, Maria C.

British structural biologist and crystallographer based at the University of Leeds in the early 1990s. Dr Maria C. Bewley was the principal author of the 1992 study “Crystal Structure of Chicken Annexin V”, completed in collaboration with Christopher Boustead, John H. Walker, David A. Waller, and Robert Huber. Her work contributed significantly to understanding calcium-dependent phospholipid-binding proteins and provided one of the earliest high-resolution structures of an Annexin family member.

Huber, Robert (born 1937)

German biochemist awarded the 1988 Nobel Prize in Chemistry for work on protein crystallography. His research on Annexins provided some of the first structural insights into calcium-dependent membrane binding.

James, M.N.G. (born 1937)

Canadian structural biologist whose research focused on protease and calcium-binding enzyme mechanisms. Co-author of several key reviews on calcium-binding proteins.

Kretsinger, Robert H. (born 1937)

American biochemist who discovered the EF-hand motif, a defining structural feature of calcium-binding proteins. His research clarified the geometric basis of calcium coordination in biological systems.

Strynadka, Natalie C.J. (born 1966)

Canadian structural biologist who worked with James on the crystallographic elucidation of enzyme and calcium-binding structures, later pioneering structural studies of membrane proteins.

Swain, Alan L.

Co-researcher with Kretsinger and Amma, contributing to quantitative analyses of calcium-binding site geometries using X-ray diffraction.

Voet, Donald (born 1941) and Voet, Judith G. (born 1943)

American biochemists and co-authors of Biochemistry, one of the most influential textbooks integrating molecular structure with biological function.

Walker, John H.

British biochemist based at the University of Leeds whose research focused on membrane-associated proteins, especially Annexins and phospholipid-binding dynamics.

Waller, David A.

Leeds-based structural biologist and co-author of studies on Annexin V crystal structure and membrane-binding behaviour.

Disclaimer

The views, interpretations, and reflections expressed in this essay are those of the author and do not necessarily represent the positions of the University of Leeds or any affiliated institution.

Essay: Continuous Wave and Fourier Transform NMR Techniques

A Discussion of Continuous Wave and Fourier Transform Techniques in Nuclear Magnetic Resonance Experiments

A visual symphony of resonance: continuous-wave signals evolve into a Fourier-transformed spectrum beneath swirling magnetic field lines. The composition celebrates the transition from analogue to digital spectroscopy that reshaped molecular analysis in the early 1990s.

Author:  Adisha Kariyawasam BSc Molecular Biophysics, MScIT, PGCE (PCET), BCS
Originally written Autumn 1992, BSc (Hons) Molecular Biophysics, University of Leeds

Republished and expanded 2025

Preface (2025 Edition)

This essay was produced in 1992 during the Spectroscopic Methods in Biophysics module at the University of Leeds. It examined how developments in Nuclear Magnetic Resonance (NMR) instrumentation revolutionised the study of molecular structure.

At that time, Fourier Transform NMR (FT-NMR) was replacing the older Continuous Wave (CW) approach, greatly increasing sensitivity and resolution. The essay sought to explain how both methods operate and why the transition to FT marked a paradigm shift in molecular spectroscopy.

A Discussion of Continuous Wave and Fourier Transform Techniques in NMR Experiments

Introduction

Nuclear Magnetic Resonance (NMR) spectroscopy provides molecular-level insight into structure, motion, and dynamics. Early NMR spectrometers employed the Continuous Wave (CW) method, in which a single monochromatic radio-frequency signal was slowly swept across the spectral range. In the early 1970s, this was superseded by the Fourier Transform (FT) method, where a short, intense pulse simultaneously excites all nuclear frequencies and the resulting signal is mathematically decomposed into its frequency components by the Fourier transform.

The two techniques illustrate the evolution from sequential to parallel data acquisition in physical chemistry.

Instrumentation

CW NMR Spectrometer:
A crystal oscillator generates a stable radio-frequency (RF) field, swept gradually through resonance while the magnetic field remains constant. The signal is monitored using an amplifier and chart recorder. Stability is maintained through field–frequency locking.

FT NMR Spectrometer:
In FT systems, a powerful RF pulse (≈ 1 kW, < 5 μs) excites all resonant nuclei simultaneously. The resulting free-induction decay (FID) is digitised and processed by a computer that performs the Fourier transform to produce the spectrum.

Modern instruments contain separate transmitter channels for field locking, observation, and decoupling, along with superconducting magnets (1.5 – 12 T) to ensure high field strength and homogeneity. Fine adjustments are achieved using shim coils, which compensate for magnetic gradients and thermal drift.

Sample Preparation and Requirements

NMR samples are usually liquid or solution phase and housed in precision glass tubes. For proton (¹H) studies, 5 mm tubes are typical, while 13 C studies may require 10–12 mm tubes. Because NMR is relatively insensitive, sample concentrations of around 1 % are often necessary.

Spinning the sample at about 15 Hz averages magnetic field inhomogeneities, improving line-shape. Temperature control is maintained by passing pre-heated or pre-cooled nitrogen gas around the sample tube. Reference compounds, such as tetramethylsilane (TMS), provide chemical-shift standards.

CW Technique: Principle and Limitations

In CW NMR, resonance absorption is detected while the magnetic field or RF frequency is slowly varied. Each resonance is observed individually, and a full spectrum may require hundreds of seconds to record.

Because signals are weak, multiple scans are averaged to improve the signal-to-noise ratio, but this process is time-consuming. Resolution is further limited by field instability and mechanical drift in scanning systems. For nuclei less sensitive than ¹H, such as ¹³C, the CW approach becomes impractical.

This slow, sequential process may be likened to “tuning each piano note in turn” to identify its frequency.

Fourier Transform Technique: Principle and Advantages

The FT method replaces frequency scanning with time-domain excitation. A single broadband RF pulse simultaneously perturbs all nuclear spins. As these spins relax, they emit the free-induction decay (FID) signal, which contains the complete frequency information of the system. The spectrometer’s computer applies a Fourier transform to convert this time-domain signal into a frequency-domain spectrum.

Because many signals are captured at once, multiple scans can be accumulated quickly, improving the signal-to-noise ratio in proportion to the square root of the number of scans.

The FT method allows for multinuclear detection (¹H, ¹³C, ¹⁵N, ³¹P), two-dimensional NMR, and advanced pulse sequences. It also enables decoupling experiments, where specific nuclei are selectively irradiated to simplify spectra or reveal coupling constants.

Practical Considerations and Artefacts

The FID must be detected after a short “dead time,” the period immediately following the RF pulse when receiver circuits recover from saturation. Proper tuning and shimming minimise artefacts such as baseline distortion or “ringing.”

Temperature control remains critical: heating may broaden lines by inducing molecular motion, while cooling increases viscosity and relaxation times. The absence of mechanical scanning in FT NMR eliminates drift artefacts common in CW spectra.

Comparative Summary

Feature	CW NMR	FT NMR
Data acquisition	Sequential	Simultaneous (time-domain)
Speed	Slow (minutes per spectrum)	Rapid (seconds)
Sensitivity	Low	High; improved by signal averaging
Resolution	Limited by mechanical drift	High; field stability and digital precision
Multinuclear capability	Usually ¹H only	Multi-nuclear (¹H, ¹³C, ¹⁵N etc.)
Data processing	Analogue	Digital via Fourier transform
Applications	Routine chemistry, early biophysics	Modern biomolecular, medical, and solid-state NMR

Applications in Molecular Biophysics

The rise of FT NMR allowed researchers to analyse large biomolecules such as peptides, nucleic acids, and small proteins in solution. High-field instruments at the Astbury Centre in Leeds were among the first in the UK to explore conformational dynamics using pulse sequences that revealed coupling networks and hydrogen-bond patterns.

The ability to detect nuclei other than ¹H, such as ¹³C and ¹⁵N, provided complementary information to X-ray crystallography, illuminating molecular motion rather than static structure.

Conclusion

The transition from Continuous Wave to Fourier Transform NMR represents a milestone in molecular spectroscopy. CW techniques laid the foundation, but FT methods transformed NMR into a versatile, high-resolution tool for chemical, biological, and medical research.

By capturing all resonances simultaneously and applying computational analysis, FT NMR embodies the very principle that defines modern biophysics: extracting dynamic molecular information from static physical laws.

Afterword (2025 Reflection)

Since 1992, NMR technology has advanced even further with cryoprobes, hypermolar polarisation, and solid-state NMR enabling detailed analysis of entire proteins, membranes, and metabolic networks. Today’s multi-dimensional NMR maps not only static structures but also the motions that underpin biological function—realising, in practice, the very idea A.V. Hill resisted: that even in apparent stillness, molecules “wriggle.”

References (Harvard Format)

• Abraham, R.J., Fisher, J. and Lochinvar, P. (1988) Introduction to NMR Spectroscopy. Chichester: Wiley.

• Derome, A.E. (1987) Modern NMR Techniques for Chemistry Research. Oxford: Pergamon Press.

• Harris, R.K. (1983) NMR Spectroscopy: A Practical Approach. London: Longman.

• Lauterbur, P.C. (1973) ‘Image formation by induced local interactions: Examples employing NMR,’ Nature, 242, pp. 190–191.

• Wüthrich, K. (1986) NMR of Proteins and Nucleic Acids. New York: Wiley-Interscience.

Appendix 1 – Glossary of Key Terms

Term	Definition
Chemical Shift	Variation in NMR resonance frequency caused by the local electronic environment of a nucleus.
CW (Continuous Wave) NMR	Traditional NMR method using a continuous RF signal scanned across resonance frequencies.
Decoupling	Technique in which one type of nucleus is continuously irradiated to remove spin–spin coupling effects.
FID (Free Induction Decay)	The time-domain signal emitted by excited nuclei after an RF pulse.
Fourier Transform	Mathematical process converting time-domain data into frequency-domain spectra.
Homogeneity	Uniformity of the magnetic field across the sample volume.
Pulse Sequence	A defined series of RF pulses and delays used to manipulate nuclear spins in NMR experiments.
Shim Coils	Auxiliary coils used to correct magnetic field inhomogeneities.
Signal-to-Noise Ratio	Measure of spectral clarity; improves with repeated signal averaging.
TMS (Tetramethylsilane)	Standard reference compound for defining zero chemical shift in ¹H and ¹³C NMR.

Appendix 2 – Short Biographies of Scientists Mentioned (Alphabetical by Surname)

Abraham, Raymond J. (1931–2014)

British physical chemist and NMR pioneer, known for integrating quantum-chemical calculations with NMR data to interpret molecular structure. His textbook Introduction to NMR Spectroscopy (1988) became a standard reference in chemical education.

Derome, Anthony E. (1942–1990)

Chemist at the University of Cambridge who advanced pulse-programming techniques for FT NMR. His Modern NMR Techniques for Chemistry Research (1987) unified the theoretical and practical aspects of time-domain spectroscopy.

Harris, Robin K. (1939–2022)

British spectroscopist and author of foundational works on NMR methodology. Harris promoted the practical application of FT NMR in both academic and industrial chemistry.

Lauterbur, Paul Christian (1929–2007)

American chemist and 2003 Nobel Laureate in Physiology or Medicine. He discovered magnetic-field gradient imaging using NMR signals, giving rise to Magnetic Resonance Imaging (MRI).

Wüthrich, Kurt (born 1938)

Swiss chemist awarded the 2002 Nobel Prize in Chemistry for developing NMR methods to determine the three-dimensional structures of biological macromolecules in solution.

Disclaimer

The views, interpretations, and reflections expressed in this essay are those of the author A. Kariyawasam and do not necessarily represent the positions or opinions of staff at the University of Leeds or any affiliated institution.

Essay: The Hydrogen Bond in Molecular Physiology

The Hydrogen Bond in Molecular Physiology

Author:  Adisha Kariyawasam BSc Molecular Biophysics, MScIT, PGCE (PCET), BCS

Originally written Autumn 1992, BSc (Hons) Molecular Biophysics, University of Leeds

Republished and expanded 2025

Preface (2025 Edition)

This second essay in the Molecular Biophysics series was written in 1992 while studying protein structure and macromolecular interactions at the University of Leeds. The hydrogen bond - once viewed as a minor chemical curiosity - was being recognised as the cornerstone of molecular structure and biological stability.

In this essay, I examined the central claim by Linus Pauling that hydrogen bonding might prove “more significant for physiology than any other single structural feature.” The work set out to test this claim by exploring the role of hydrogen bonds in proteins, membranes, nucleic acids, and connective tissue.

The Hydrogen Bond in Molecular Physiology

“It has been recognised that hydrogen bonds restrain protein molecules to their native configurations, and I believe that as the methods of structural chemistry are further applied to physiological problems it will be found that the significance of the hydrogen bond for physiology is greater than that of any other single structural feature.”
(Pauling, 1939 in The Nature of the Chemical Bond)

 

Introduction

Pauling’s statement was both visionary and provocative. To evaluate its accuracy, one must ask three key questions:

1. What experimental techniques reveal hydrogen bonds in biological molecules?

2. To what extent do these bonds restrain molecular motion and structure?

3. What physiological roles do such interactions perform?

Techniques for Studying Hydrogen Bonds

• X-ray Diffraction shows that strong hydrogen bonds shorten the expected van der Waals distances by 0.2–0.3 Å.

• Nuclear Magnetic Resonance (NMR) detects characteristic shifts in proton resonance when hydrogen bonding occurs.

• Infra-red (IR) Spectroscopy reveals frequency shifts in stretching and bending modes (e.g. C=O and N–H) that mark the presence of hydrogen bonds.

Together these methods provide a three-dimensional and dynamic picture of bonding within and between macromolecules.

Proteins and the Role of Hydrogen Bonds

Hydrogen bonds are fundamental to protein conformation. Water molecules at a protein’s surface form extensive hydrogen-bonded networks, while interior residues maintain tight intra-chain bonding.

On a protein’s surface, polar side-chains can create or disrupt hydrogen bonds, altering reactivity. The best-known example is haemoglobin, in which hydrogen bonds influence oxygen affinity.

• In oxyhaemoglobin, breaking specific hydrogen bonds allows oxygen binding.

• In deoxyhaemoglobin, hydrogen bonds involving histidines 58 and 87 stabilise the low-oxygen form.

Mutations such as Haemoglobin Thionville (Vasseur et al., 1987) modify hydrogen-bonding at subunit interfaces, demonstrating how small structural changes can affect oxygen transport and stability.

Membranes and Ion Transport

Hydrogen bonds are also vital in membrane physiology. Ionophores such as valinomycin employ rearrangements of six carbonyl oxygen atoms, held by internal hydrogen bonds, to complex potassium ions. This dynamic bonding enables selective ion transport across membranes - an essential feature of bioenergetics.

In transmembrane proteins, regular hydrogen-bonding patterns stabilise α-helices and β-sheets that traverse lipid bilayers. Loss of these interactions can cause chain bending or pore collapse, compromising membrane integrity.

Helices and Structural Frameworks

Collagen

The collagen triple helix is stabilised by inter-chain hydrogen bonds involving hydroxyproline and hydroxylysine. Vitamin C deficiency prevents hydroxylation, weakening these bonds and leading to collagen degradation - a molecular explanation for scurvy.

DNA Double Helix

The DNA double helix, the molecule of heredity, owes its stability to hydrogen-bonded base pairs—adenine with thymine, guanine with cytosine - complemented by hydrophobic stacking. The pairing rules encode genetic fidelity.

Gene Regulation

Hydrogen bonds also guide protein – DNA recognition. In bacteriophage λ, the CRO repressor binds to its operator region through a specific pattern of hydrogen-bond donors and acceptors within the DNA’s major groove. This precise bonding determines whether the phage enters lysogenic or lytic pathways.

Molecular Recognition and Immunology

Hydrogen bonding governs the specificity of antibody–antigen interactions. In the FAB D1.3–lysozyme complex, six complementarity-determining regions (CDRs) form a dense network of hydrogen bonds that position antigen residues for recognition.

A single substitution - replacing glutamine 121 with histidine in Californian quayle lysozyme - breaks one crucial hydrogen bond, lowering binding energy by ≈ 40 kJ mol⁻¹ and abolishing affinity. This striking sensitivity exemplifies the precision of hydrogen bonding in immune recognition.

Carbohydrates and the Extracellular Matrix

Hydrogen bonds stabilise the polysaccharide frameworks of the extracellular matrix. In glycoproteins and proteoglycans, extensive hydrogen bonding confers both elasticity and hydration. Components such as hyaluronate form helical structures whose viscosity arises from hydrogen-bonded water networks.

Fibrous proteins (collagen, elastin, fibronectin, laminin) interweave with these polysaccharides, forming the molecular scaffold of tissues. Even cellulose, the structural polymer of plants, derives its rigidity from hydrogen bonds between adjacent chains - arguably biology’s most widespread structural motif.

Conclusion: Is Pauling Vindicated?

The examples above confirm that hydrogen bonds pervade every level of biological organisation—from enzyme catalysis to connective tissue mechanics. While other forces (ionic, van der Waals, disulphide bridges) also contribute, none rival the ubiquity of the hydrogen bond.

Pauling’s prediction has been amply fulfilled: hydrogen bonding is not merely significant but central to molecular physiology. As later commentators have suggested (Chang, 1981), if anything, its importance may once have been underestimated.

Afterword (2025 Reflection)

Modern structural biology has deepened our understanding of hydrogen bonding beyond Pauling’s imagination. Cryo-EM, ultrafast spectroscopy, and quantum simulations now reveal the fleeting vibrations and proton transfers that animate molecular life.

Hydrogen bonds are no longer seen as static connections but as dynamic conduits of energy and information. From protein folding algorithms to enzyme design and DNA nanotechnology, the “hydrogen-bond code” continues to shape the frontier of molecular medicine.

References (Harvard Format)

• Chang, R. (1981) Physical Chemistry with Applications to Biological Systems. New York: Macmillan.

• Kendrew, J.C. (1963) ‘Structural Biology: The New Landscape’, Scientific American, 208 (5), pp. 96–108.

• Pauling, L. (1939) The Nature of the Chemical Bond. Ithaca: Cornell University Press.

• Vasseur, C., et al. (1987) ‘Haemoglobin Thionville: Functional and structural analysis’, Journal of Biological Chemistry, 262 (18), pp. 12682–12691.

• Chang, R. (1981) Physical Chemistry with Applications to Biological Systems, 2nd edn. New York: Macmillan.

Appendix 1 – Glossary of Key Terms

Term	Definition
α-Helix / β-Sheet	Common protein secondary structures stabilised by hydrogen bonds between backbone atoms.
Antibody (Immunoglobulin)	A protein produced by B cells that recognises specific antigens.
Base Pairing	Hydrogen-bonded interaction between nucleotide bases in DNA and RNA.
Collagen	A fibrous structural protein whose triple-helix stability depends on inter-chain hydrogen bonding.
Hydrogen Bond	A weak electrostatic attraction between a hydrogen atom covalently bonded to an electronegative atom (e.g. O or N) and another electronegative atom with a lone pair.
Ionophore	A molecule that facilitates ion transport across membranes via reversible binding.
Lysozyme	An enzyme that hydrolyses bacterial cell-wall polysaccharides; a model protein for studying molecular recognition.
NMR Spectroscopy	Technique exploiting magnetic properties of nuclei to study molecular structure.
Proteoglycan	A glycoprotein rich in polysaccharides forming part of connective tissue matrices.
Scurvy	Disease caused by vitamin C deficiency, leading to impaired collagen hydroxylation and weakened hydrogen bonding.

Appendix 2 – Short Biographies of Scientists Mentioned (Alphabetical by Surname)

Chang, Raymond (1939–2017)

Chinese-American physical chemist and textbook author. His Physical Chemistry with Applications to Biological Systems (1981) brought thermodynamics and bonding concepts into biochemical education, influencing generations of molecular scientists.

Engström, Lars

Swedish biochemist known for work on cell ultrastructure with James B. Finean. Their 1969 book Biological Ultrastructure helped establish structural approaches to cell biology.

Finean, James B. (1913–1987)

British biophysicist who elucidated membrane structure through electron microscopy and diffraction studies. His collaboration with Engström linked macroscopic tissue structure to molecular organisation.

Kendrew, John Cowdery (1917–1997)

British structural biologist who, with Max Perutz, solved the first protein structures (myoglobin and haemoglobin) by X-ray crystallography. He shared the 1962 Nobel Prize in Chemistry.

Pauling, Linus Carl (1901–1994)

American chemist and molecular biologist awarded the 1954 Nobel Prize in Chemistry and the 1962 Nobel Peace Prize. His concept of the chemical bond and prediction of α-helices and β-sheets formed the foundation of modern structural biology.

Vasseur, Claude

French biochemist whose late-1980s work on mutant haemoglobins (e.g. Haemoglobin Thionville) demonstrated how altered hydrogen bonding affects oxygen transport and allosteric regulation.

Disclaimer

The views, interpretations, and reflections expressed in this essay are those of the author A. Kariyawasam and do not necessarily represent the positions or opinions of staff at the University of Leeds or any affiliated institution.

Essay: The Relevance of Structural Molecular Biology to Medicine

The Relevance of Structural Molecular Biology to Medicine

A conceptual rendering of molecular medicine: a DNA double helix merges into a protein ribbon against an X-ray diffraction field, symbolising the continuum between structure and human health that defined early molecular biophysics at the University of Leeds (1992).

Author: Adisha Kariyawasam Molecular Biophysics, MScIT, PGCE (PCET), BCS

Originally written 15 November 1992, BSc (Hons) Molecular Biophysics, University of Leeds
Republished and expanded, 2025

Preface (2025 Edition)

This essay was originally written in November 1992 during my second year as an undergraduate in Molecular Biophysics at the University of Leeds. It reflects a formative period of my understanding of  structural biology, when the relationships between molecular structure and disease were first becoming clear through advances in X-ray crystallography, molecular genetics, and the emerging field of protein engineering.

At that time, the question “What is the relevance of structural molecular biology to medicine?” stood at the frontier of interdisciplinary science. The essay focuses on one particular area - oncology - as a way of exploring how the study of molecular architecture could illuminate the understanding and treatment of disease.

The Relevance of Structural Molecular Biology to Medicine

Introduction

Over the past decades, remarkable progress has been made in understanding the molecular structure of life. But what relevance does this have to medicine? It would be impossible to survey all aspects of molecular biology relevant to medical science; however, one field - oncology, the study of cancer - provides a compelling focus through which to examine the link between molecular structure and disease.

In the early days of structural biology, the physiologist Archibald Vivian Hill - Nobel laureate for his pioneering studies of muscle physiology - famously dismissed crystallography’s biological value with the remark:

“That’s no good - crystals don’t wriggle, and if they don’t wriggle, it’s not biology.”
(Hill, quoted in Perutz, 1987, p. 56)

Hill’s scepticism captured a prevailing sentiment: that static crystal structures could never explain the dynamic nature of living systems. Yet it was precisely through these “non-wriggling crystals” that the foundations of molecular medicine were laid, transforming the diagnosis and treatment of disease.

Molecular Biology and the Architecture of Life

Structural molecular biology seeks to unravel the atomic frameworks underpinning biological processes, linking the physical and chemical properties of macromolecules to their physiological roles. Within living cells, macromolecules - proteins, nucleic acids, carbohydrates, and lipids—interact to sustain life. These interactions determine how energy is transferred, how cells communicate, and how genetic information is expressed and regulated.

By elucidating molecular structure, scientists have uncovered the intimate relationship between form and function - a relationship that lies at the heart of all biological activity.

Molecular Recognition

The study of molecular recognition - how biological molecules identify and bind to specific partners - has revealed the intricate logic of life at the atomic scale. Enzyme catalysis, antigen–antibody specificity, and receptor–ligand interactions all depend on the precise folding of protein macromolecules.

For instance, the serine protease family (trypsin, chymotrypsin, and elastase) exhibits near-identical three-dimensional structures across widely differing organisms, despite variations in sequence. This conservation shows that evolution has optimised structural motifs for efficiency and resilience.

Biological systems therefore exhibit spatial and temporal molecular patterns: three-dimensional arrangements that define how and when biochemical events occur.

Macromolecules in Advanced Systems

Even the simplest living systems are molecularly complex. The nucleoprotein virus, for example, contains all the information necessary for self-replication - but only within a suitable cellular environment. Such simplicity belies extraordinary sophistication at the molecular level.

As evolution progressed, increased molecular complexity led to specialised structures, elaborate metabolic pathways, and finely tuned control systems. Medicine, by contrast, concerns itself with understanding and repairing these systems when they fail.

Molecular Function and Genetic Control

Our understanding of how complex macromolecules arise from simple precursors continues to grow. Nucleic acids store genetic information, while proteins act as catalysts, regulators, and structural elements. Together, they embody the central dogma of molecular biology—DNA makes RNA makes protein.

Environmental conditions can influence gene expression, as shown in tissue culture and embryonic transplantation experiments (Engström and Finean, 1969). Yet, despite these influences, the organism’s genetic material sets the boundaries for development and differentiation.

In this sense, medicine and molecular biology converge: both seek to understand how the expression of genetic information shapes health and disease.

Genetics and Disease

Molecular genetics has provided powerful techniques for studying human disease. The use of DNA probes, restriction enzyme mapping, and blotting techniques has made it possible to detect specific mutations responsible for inherited disorders. For example, changes in DNA restriction patterns can indicate chromosomal abnormalities or deletions.

Although these early methods were limited to detecting large alterations, they laid the groundwork for today’s genomic medicine. Questions about the role of non-coding DNA - the so-called C-value paradox - continue to inspire new discoveries, particularly in the regulation of gene expression.

Molecular Defects and Pathology

Pathological conditions often stem from molecular defects. In sickle-cell anaemia, a single amino-acid substitution (glutamic acid to valine at position six) in the β-chain of haemoglobin alters its structure, leading to polymerisation and reduced oxygen-binding capacity.

Analogously, a similar substitution (Glu¹²→Val) has been observed in the p21 protein isolated from bladder carcinoma cells (McKenna, 1983). In such cases, small molecular defects can have profound physiological consequences.

Moreover, some molecular defects render cells more sensitive to environmental factors, such as air pollutants or carcinogens, which may in turn trigger the onset of cancer.

Oncogenes and Oncoproteins

The discovery of oncogenes - mutated or overactive versions of normal cellular genes known as proto-oncogenes - has been one of the defining achievements of molecular medicine. Proto-oncogenes normally regulate cell growth and differentiation, but when activated through mutation, amplification, or chromosomal translocation, they can drive malignancy (Ellis and Sikora, 1987).

Their protein products, oncoproteins, act as molecular switches within complex signalling cascades. Through advances in oligopeptide immunisation and gene-shuffling, researchers have developed monoclonal antibodies (MCAs) that specifically target these oncoproteins (Evan, 1985; Roberts et al., 1987).

Recent innovations have gone further: immunotoxins, or “magic bullets,” combine monoclonal antibodies with toxins such as saporin, selectively recognising and destroying tumour cells expressing heat shock proteins (Poccia et al., 1992).

Such work exemplifies how structural molecular biology provides not only understanding but also intervention.

From Structure to Therapy

The union of structural insight and computational modelling has revolutionised therapeutic design. High-resolution crystallography, nuclear magnetic resonance (NMR) spectroscopy, and molecular dynamics simulations enable scientists to visualise the very interactions that determine drug efficacy and side effects.

These approaches have given rise to targeted therapies - small-molecule inhibitors, monoclonal antibodies, and engineered peptides - that treat disease with unprecedented precision. The concept that “structure determines function” is now the foundation of precision medicine.

Conclusion

Diseases often result from breakdowns in molecular coordination - defects in enzymatic control, signal transduction, or gene regulation. Structural molecular biology provides the means to identify, understand, and rectify these defects.

As Max Perutz (1989) observed, “protein structure holds the key to understanding disease.” The insights drawn from static crystal structures have revealed the underlying motions of life itself, proving A.V. Hill’s famous quip profoundly ironic. Crystals do “wriggle” - at least in the imagination of structural biologists - and through them, medicine has learned to see life at atomic resolution.

Afterword (2025 Reflection)

More than thirty years later, the themes explored in this essay have matured into the foundations of modern biomedicine. Structural molecular biology now extends far beyond the X-ray crystallography of the early 1990s. Techniques such as cryo-electron microscopy, single-molecule spectroscopy, and artificial intelligence–based protein folding have revealed biological detail once thought impossible.

Therapeutics based on monoclonal antibodies, protein engineering, and gene editing now routinely save lives. The “molecular keyboard” of oncogenes, once a research metaphor, has become a clinical reality through molecular diagnostics and personalised treatment.

What began as the study of static crystals has evolved into a science of living structure - a testament to the truth that, in biology, everything wriggles.

References (Harvard Format)

• Ellis, M. and Sikora, K. (1987) ‘Oncogenes and cancer: clinical implications’, Journal of the Royal College of Physicians of London, 21(2), pp. 122–127.

• Engström, L. and Finean, J.B. (1969) Biological Ultrastructure. London: Academic Press.

• Evan, G. (1985) ‘Molecular approaches to oncoprotein immunisation’, Molecular and Cellular Biology, 5, p. 3610.

• Hill, A.V. (quoted in Perutz, M.F. 1987) Is Science Necessary? Essays on Science and Scientists. Oxford: Oxford University Press, p. 56.

• Lasserre, C. et al. (1992) ‘Activation of the HIP gene in human primary liver cancer’, Cancer Research, 52(18), pp. 5089–5095.

• McKenna, P.G. (1983) ‘Molecular defects in bladder carcinoma’, Irish Medical Journal, 76(8), pp. 237–240.

• Perutz, M.F. (1989) Protein Structure: New Approaches to Disease and Therapy. Oxford: Oxford University Press.

• Poccia, F. et al. (1992) ‘Use of immunotoxins in targeting heat shock proteins in tumour cells’, British Journal of Cancer, 66(3), pp. 427–432.

• Roberts, S. et al. (1987) ‘Monoclonal antibody design using gene-shuffling techniques’, Nature, 328, pp. 731–733.

Appendix 1: Glossary of Key Terms

Term	Definition
Amino acid	The basic building block of proteins, consisting of an amino group, a carboxyl group, and a side chain (R group) that determines its chemical properties.
Antibody	A protein produced by the immune system that specifically recognises and binds to foreign antigens.
Central dogma	The fundamental principle of molecular biology: DNA → RNA → Protein.
Cryo-electron microscopy (cryo-EM)	A modern imaging technique that allows biological molecules to be visualised at near-atomic resolution without crystallisation.
DNA probe	A short, labelled DNA fragment used to detect complementary sequences in genetic analysis.
Gene expression	The process by which genetic information is transcribed and translated into proteins.
Macromolecule	A large molecule such as a protein, nucleic acid, or polysaccharide essential for life’s processes.
Monoclonal antibody (MCA)	An antibody produced by a single clone of cells, identical in structure and specificity, used in diagnostics and therapy.
Oncogene	A gene that has the potential to cause cancer when mutated or abnormally expressed.
Oncoprotein	The protein product of an oncogene, often involved in the regulation of cell growth and division.
Protein folding	The process by which a protein assumes its functional three-dimensional structure.
Proto-oncogene	A normal gene that can become an oncogene due to mutation or increased expression.
Restriction enzyme	A bacterial enzyme that cuts DNA at specific sequences, used in genetic mapping and molecular cloning.
Saporin	A ribosome-inactivating protein used in immunotoxins to destroy targeted cells.
Serine protease	A family of enzymes that use a serine residue in their active site to catalyse the cleavage of peptide bonds.
Structural molecular biology	The study of the molecular structure and physical properties of biological macromolecules.

Appendix 2: Short Biographies of Scientists Mentioned

Ellis, Michael (dates not publicly recorded)
Professor Michael Ellis is a British oncologist whose collaborative work with Karol Sikora in the 1980s helped bridge molecular biology and clinical cancer research. Their studies clarified the role of oncogenes in tumour formation and progression, contributing to early frameworks for precision medicine. Ellis co-authored the 1987 Journal of the Royal College of Physicians of London paper that emphasised the clinical potential of molecular insights into cancer.

Elion, Gertrude Belle (1918–1999)
Gertrude Elion was an American biochemist and pharmacologist whose pioneering use of rational drug design transformed modern therapeutics. Awarded the 1988 Nobel Prize in Physiology or Medicine, she developed life-saving drugs for leukaemia, herpes, and AIDS. Her emphasis on molecular mechanism and enzyme targeting anticipated the structure-based drug discovery approaches that underpin much of today’s biomedical research.

Engström, Lars (dates not publicly recorded)
Lars Engström was a Swedish biochemist known for his collaborative work with James B. Finean on cellular ultrastructure. Their 1969 text Biological Ultrastructure provided one of the earliest comprehensive analyses of how macromolecular organisation influences cell function. Engström’s work helped establish the conceptual bridge between cell morphology and molecular biophysics.

Evan, Geoffrey M. (born 1952)
Commonly known as Gerard Evan, this British molecular biologist is recognised for his research on oncogene function and apoptosis. His early 1980s work on molecular immunisation and oncoprotein regulation connected structural understanding with cancer immunotherapy. His 1985 paper in Molecular and Cellular Biology exemplified the shift toward translational research that merged molecular structure with medical application.

Finean, James B. (1913–1987)
James B. Finean was a British biophysicist who collaborated with Lars Engström on the study of cellular and membrane ultrastructure. Their joint work clarified how lipid and protein components assemble to form biological membranes, reinforcing the idea that biological form and molecular organisation are inseparable. Finean’s research influenced later developments in structural biology and membrane biophysics.

Hill, Archibald Vivian (1886–1977)
A.V. Hill was a pioneering British physiologist and one of the founders of biophysics. He was awarded the 1922 Nobel Prize in Physiology or Medicine (shared with Otto Meyerhof) for his discoveries on the production of heat in muscle. Hill’s quip, “That’s no good — crystals don’t wriggle, and if they don’t wriggle, it’s not biology,” reflected his early scepticism toward crystallography. Ironically, his emphasis on quantitative methods and physical principles paved the way for modern molecular physiology.

Kendrew, John Cowdery (1917–1997)
John Kendrew was a British biochemist and structural biologist who, together with Max Perutz, shared the 1962 Nobel Prize in Chemistry for their elucidation of the structures of globular proteins via X-ray crystallography. His model of myoglobin was the first atomic-resolution protein structure ever determined. Kendrew’s achievements validated the power of crystallography to reveal biological function, contradicting Hill’s famous assertion.

Lasserre, Charles (dates not publicly recorded)
Dr Charles Lasserre was a French cancer researcher active during the late 1980s and early 1990s. His team’s work on the HIP gene in human liver cancer (published in Cancer Research, 1992) provided early molecular evidence of gene activation in oncogenesis. Lasserre’s studies contributed to the growing understanding of genetic regulation in tumour biology.

McKenna, Peter G. (dates not publicly recorded)
Dr Peter G. McKenna was an Irish clinician and molecular biologist whose research in the early 1980s explored molecular defects in human cancers. His 1983 Irish Medical Journal paper on bladder carcinoma demonstrated how specific amino acid substitutions in proteins could influence tumour development. McKenna’s work exemplified the clinical application of molecular genetics to pathology.

Perutz, Max Ferdinand (1914–2002)
Max Perutz was an Austrian-born British molecular biologist who pioneered the field of protein crystallography. He shared the 1962 Nobel Prize in Chemistry with John Kendrew for determining the structure of haemoglobin. Perutz’s later works, including Is Science Necessary? (1987) and Protein Structure: New Approaches to Disease and Therapy (1989), reflected deeply on the social and medical dimensions of molecular science. His research revealed how structural changes in proteins underpin both normal physiology and disease.

Poccia, Federico (1948–2004)
Federico Poccia was an Italian biochemist whose research advanced understanding of immunotoxins and immune cell development. His 1992 British Journal of Cancer paper explored the use of monoclonal antibodies conjugated with toxins to target tumour-specific heat shock proteins. Poccia’s work exemplified the move from molecular understanding to molecular therapeutics.

Roberts, Stephen (dates not publicly recorded)
Stephen Roberts is a molecular biologist best known for his late-1980s work on recombinant antibody design and gene-shuffling, published in Nature. His research contributed to the evolution of monoclonal antibody technology and the concept of engineered immunotherapy, bridging molecular structure and clinical application.

Sikora, Karol (born 1948)
Professor Karol Sikora is a British oncologist, medical educator, and cancer policy advocate. As co-author of early papers on oncogenes with Michael Ellis, Sikora was instrumental in linking molecular mechanisms with clinical oncology. He later served as Director of the WHO Cancer Programme. Sikora’s career exemplifies the translation of molecular biology into evidence-based cancer treatment.

Wrighton, Stephen A. (1951– )
While not a direct source in the essay, Stephen Wrighton’s contributions to molecular pharmacology during the late 1980s - particularly in cytochrome P450 enzyme characterisation - represent the broader scientific milieu of structural molecular medicine. His work exemplified the biochemical precision the essay advocates, where understanding enzyme structure informs pharmacological design.

Disclaimer

The views, interpretations, and reflections expressed in this essay are those of the author A. Kariyawasam and do not necessarily represent the positions or opinions of staff at the University of Leeds or any affiliated institution.