Chemistry & Crystals

The year was 1932, and Oxford University had just awarded a first-class degree to a woman for only the third time in its history.

 

The woman in question was Dorothy Crowfoot Hodgkin: a scientist who would go on to revolutionise biochemistry, leaving behind a legacy that has fundamentally shaped our understanding of living organisms and supported the growth of modern medicine.

 

Born in Cairo in 1910, Hodgkin’s love for science was nurtured by her parents: a pair of English archaeologists living as expatriates in Egypt. At 15, the young Dorothy was given a children’s book written by the great scientist, William Henry Bragg, on the topic of an exciting new technique known as ‘crystallography’.

 

William Henry Bragg and his son Lawrence had discovered some years earlier that it was possible to ‘see’ the individual atoms and molecules inside crystallised materials – like a grain of salt – by exposing them to X-rays. Their findings had opened up an entirely new world in which it was possible to explore things thousands of times smaller than could be seen with a regular microscope.

 

 

It was an exciting time for science, and the young Dorothy was, in her own words: “captured for life by chemistry and by crystals.” She would go on to gain her chemistry degree from Oxford, before moving on to a PhD at Cambridge. And it was here, in 1932, that Hodgkin began shaping the field that would grow into her greatest legacy: protein crystallography.

 

From the beating of our hearts to the survival of our cells, proteins are at the very core of natural life. Thousands of times smaller than a pinhead, these complex groups of molecules are responsible for virtually all of the processes that take place in our bodies. And by discerning their atomic structure, scientists can work out how proteins function and design drugs that regulate their behaviour, helping us to fight disease.  

 

Our in-depth understanding of proteins has helped us to create a better world, but a great deal of what we know now would not have been possible were it not for Hodgkin and her pioneering spirit.

 

At Cambridge, the young Hodgkin was given a sample of pepsin: one of the key enzymes in the digestive system. Hodgkin was aware that crystallography could be used to explore the intricate atomic structure of materials, but it was only widely used to explore minerals like salt and copper. Crystallography experiments on biological matter were still in their infancy, and no-one had ever before attempted to explore proteins using the technique.

But together with her supervisor, the ingenious J. D. Bernal, Hodgkin resolved to apply the novel technique to their pepsin sample. The experiment proved successful, and within the year the team held in their hands an X-ray photograph of pepsin.

 

Hodgkin and Bernal’s gamble had paid off. They had the pepsin diffraction pattern, but they also had much more than that. The pair had decisively proven that X-ray crystallography could be applied to biological proteins, and that it could ultimately help scientists to uncover their atomic structure. In doing they had launched into groundbreaking scientific terrain.

 

 

The field of protein crystallography was born. From here, scientists would go on to use the technique to study a huge number of biological substances, from viruses to vitamins. And the decades that followed saw one extraordinary discovery after another, as the powerful technique was embraced by scientists around the world.

 

In 1964, Hodgkin achieved another first, becoming the only British woman ever to win a Nobel prize for science. The award for Chemistry was bestowed in recognition of Hodgkin’s “determinations by X-ray techniques of the structures of important biochemical substances."

 

The accolade couldn’t have been more deserved. Over the course of her lifetime, Hodgkin would unravel the atomic structures of, amongst others, cholesterol, penicillin, vitamin B12, and insulin. Her work on insulin, in particular, took 35 years to complete and has underpinned vital therapies for diabetes.

 

The insights Hodgkin revealed into biochemistry helped to support many improvements in public health and medicine.

 

More than 120,000 protein structures have now been solved, and protein crystallography is still very much in use today. But we’ve come a long way since the days of Hodgkin and her peers.

 

Using the X-ray light produced at synchrotrons, it’s now possible for scientists to determine atomic structure more quickly than ever before. In fact, the work on insulin that took 35 years to complete could now be done in a single hour.

 

But none of this would have been possible were it not for the tireless efforts of Dorothy Crowfoot Hodgkin and her peers at the forefront of X-ray crystallography.

 

In science, we are always standing on the shoulders of giants. Thanks to Hodgkin and others like her, we can now study the atoms and molecules that allow living organisms to function, helping us to fight disease and save lives.

 

Hodgkin revealed the complex beauty and significance of a world that remains out of sight for most of us. And in doing so, she helped scientists everywhere to venture into the unknown and explore the very stuff that life is made of.