Skip to main content
The First PhotographThe Mathematics of ShadowsThe Penicillin DetourThe B12 Problem and the First ComputersThe Return to InsulinWorking Through the PainThe Legacy She BuiltThe Foundation
Science / Explained
Foundations

Dr. Dorothy Hodgkin: 34 Years and 788 Atoms

Every peptide medicine on the market today rests on precise molecular mapping. Dr. Dorothy Hodgkin mapped that baseline herself over a grueling 34-year span, entirely by hand.

8 chapters

Every peptide medicine on the market today rests on precise molecular mapping. You have to know exactly where the atoms sit in a hormone before you can build a therapy around it.

Dr. Dorothy Hodgkin mapped that baseline herself over a grueling 34-year span, entirely by hand.

01

The First Photograph

It is 1935. Dorothy Hodgkin is 25. She has just taken the first X-ray photograph of an insulin crystal.

The image is noise. Tiny specks on film standing in for 788 atoms. She will spend the next three decades working out exactly what those specks mean.

02

The Mathematics of Shadows

In 1935, X-ray crystallography meant a dark room, a tube, a crystal, and film. You take the picture. Then you do the math.

She learned the method at Cambridge under J.D. Bernal. He taught her the physics, and he taught her a refusal to round a number when it had to be exact.

She chose insulin because the molecule mattered. The prevailing medical view treated diabetes as a symptom. Hodgkin read it as a structural problem.

03

The Penicillin Detour

During World War II, she set insulin aside for a stretch to study penicillin.

The chemistry establishment was certain that a particular four-atom structure in penicillin, a beta-lactam ring, simply could not exist. The strain, they argued, would snap the molecule apart.

Hodgkin mapped it and showed they were wrong. The strain was the point. That exact tension was what made the molecule lethal to bacteria.

There is a quiet satisfaction in settling an argument with physics. The chemists debated theory. Hodgkin pointed at the film: the atoms sit where they sit.
04

The B12 Problem and the First Computers

In 1948 she took on vitamin B12. At 181 atoms, its complexity ran past what hand calculation could reach, however massive the effort.

But the hardware was catching up. Working with Alan Turing's Pilot ACE machine, Hodgkin saw what most chemists missed. Crystallography was, at bottom, a math problem waiting for enough computing power.

She learned to program in the earliest languages just to process her own data. By 1954 she had solved B12.

05

The Return to Insulin

She won the Nobel Prize in chemistry in 1964. Most people take the victory lap. Hodgkin went straight back to the insulin puzzle.

06

Working Through the Pain

By 1960, Hodgkin was 50 and living with severe rheumatoid arthritis.

The autoimmune disease was actively destroying the small joints in her hands and wrists. For someone whose work meant aligning microscopic crystals and adjusting delicate equipment, that was an enormous physical obstacle.

Instead of stopping, she built a lever-and-pulley system to trigger the X-ray switch when her fingers no longer could. She taped splints to her hands and kept working.

Why go back to insulin at all? She had the Nobel. Her legacy was secure either way. She simply meant to keep the promise she had made herself at 25, and not let the puzzle win.

She raised the funding, got IBM to donate machine time, and pushed the math forward. In September 1969, 34 years after that first photograph, she and her team published the structure in Nature.

She had placed 788 atoms locking into a hexamer. She finally knew exactly where the zinc sat.
07

The Legacy She Built

She solved roughly 100 structures over her career. Since then, the field has mapped more than 250,000 proteins. The Protein Data Bank we rely on today exists because of the foundation she laid.

A 34-year timeline might suggest a scientist working alone in a dark room. Hodgkin worked the opposite way, in deep collaboration.

In an era of strict academic formality, she had her students call her "Dorothy." When the Nobel money came, she gave most of it away to international scholarships and peace work.

Her husband was a member of the Communist Party, which led the United States to bar her from the country during the Cold War. She made the CIA issue waivers so she could attend scientific conferences.

She went anyway.

08

The Foundation

Today's GLP-1s and peptide medicines exist because of the patience of the people who built the tools. The treatments we have now are the direct result of a woman who refused to accept an incomplete answer until the film gave it up.

Supporting Material

Read further into the science.

Frequently Asked Questions
    Glossary3 terms
    X-Ray Crystallography
    A technique that produces 3D structural images of microscopic molecules from their diffraction patterns.
    Hexamer
    A 3D molecular complex built from six structural units locked together (for example, how insulin is stored).
    Beta-lactam ring
    A four-atom ring structure central to penicillin's bactericidal activity.
    References3 sources

    Crystallography & insulin structure

    1. Hodgkin DC, Kamper J, Mackay M, et al. · 1969
      Structure of rhombohedral 2 zinc insulin crystals.
      Nature 224(5218):491-495 · PMID 5344106

    Peptide structure and drug design context

    1. Fosgerau K, Hoffmann T. · 2015
      Peptide therapeutics: current status and future directions.
      Drug Discov Today 20(1):122-128 · PMID 25450771 · DOI 10.1016/j.drudis.2014.10.003
    2. Craik DJ, Fairlie DP, Liras S, Price D. · 2013
      The future of peptide-based drugs.
      Chem Biol Drug Des 81(1):136-147 · PMID 23253135 · DOI 10.1111/cbdd.12055

    Disclaimer. This article is for educational purposes only and does not constitute medical advice. Peptide signals and their therapeutic applications are complex and context-dependent.

    Next Deep Read
    A Century of Peptides
    Related articles

    Peptide Therapy History: A Century of Peptides from the First Patient to GLP-1

    From a dying boy in 1921 to a $1 patent that belonged to the world to a Gila monster's saliva. The hundred-year story of how scientists learned to turn the body's signals into medicine.

    Read more

    How are peptides made from just 20 amino acids?

    The body uses just 20 amino acids to build every peptide signal it runs. Think of these 20 amino acids as letters in an alphabet.

    Read more

    What Are Peptides? Your Body Runs on 7,000 Peptide Signals

    A deep dive into how short chains of amino acids regulate hunger, blood sugar, pain, immunity, and tissue repair across the entire body.

    Read more

    How do peptides beat the immune system to a wound?

    Cut your finger. Blood pools. Pain registers. Within seconds, the body deploys microscopic proteins to hunt bacteria and prevent infection. These proteins are peptides.

    Read more

    How do peptides work?

    How do peptides work? Peptides work by fitting specific receptors and then triggering a cellular response. That receptor-fit model explains why one peptide can regulate hunger while another affects pain, immunity, or blood sugar.

    Read more
    Keep building trust

    Move from the science to the proof, source, and practical questions.

    Science next

    What Are Peptides? Your Body Runs on 7,000 Peptide Signals

    Keep the explanation moving with the next evidence-led Science article.

    Keep learning

    Science next

    What is GLP-1?

    Keep the explanation moving with the next evidence-led Science article.

    Keep learning

    Science next

    Are peptide drugs FDA approved?

    Keep the explanation moving with the next evidence-led Science article.

    Keep learning

    Product context

    GLP-3 product page

    Move from mechanism and evidence to the GLP-3 product context.

    See GLP-3 context