Dorothy Hodgkins

Dorothy Crowfoot Hodgkin: Scientific Discoveries and Humanitarian Efforts

Dorothy Crowfoot Hodgkin: Scientific Discoveries and Humanitarian Efforts

Introduction

Dorothy Crowfoot Hodgkin was only the third woman to win the Nobel Prize in Chemistry. She was awarded the Nobel Prize for her discoveries using x-ray crystallography in 1964. Her efforts to pioneer the technique of x-ray crystallography subsequently lead to the discovery of the molecular structures of penicillin, vitamin B-12, and insulin.

This amazing woman was also a humanitarian. She was deeply involved in furthering the cause of world peace. Dr. Hodgkin was President of the Pugwash Conference and received the Lenin Peace Prize and was awarded a number of other Honorary Fellowships and Degrees for her humanitarian work.

Dorothy Hodgkin's Scientific Discoveries and Humanitarian Efforts are an inspiration. She was among few women chemists who have contributed not only scientific breakthroughs but also tremendous effort to affect the society around them. It is hoped that others might be inspired to follow her footsteps.

Scientific Discoveries

X-Ray Crystallography

Hodgkin's scientific discoveries anchored on her efforts to pioneer techniques in x-ray crystallography. This paper would be first discussing the topic of x-ray crystallography and then move on to the specific scientific discoveries of Hodgkins.

X-ray crystallography is an experimental technique that exploits the fact that X-rays are diffracted by crystals. It is not an imaging technique. X-rays have the proper wavelength (in the Ð"...ngstrÐ"¶m range, ~10-8 cm) to be scattered by the electron cloud of an atom of comparable size. Based on the diffraction pattern obtained from X-ray scattering off the periodic assembly of molecules or atoms in the crystal, the electron density can be reconstructed. "Additional phase information must be extracted either from the diffraction data or from supplementing diffraction experiments to complete the reconstruction (the phase problem in crystallography). A model is then progressively built into the experimental electron density, refined against the data and the result is a quite accurate molecular structure." (Rupp, 2005)

Crystallography, on the other hand, "which is the end goal of x-ray crystallography, is the knowledge of accurate molecular structures. It is required for structure based functional studies to aid the development of effective therapeutic agents and drugs." (Bellis 2007)

Crystallography can reliably provide the answer to many structure related questions. In contrast to NMR, which is an indirect spectroscopic method, no size limitation exists for the molecule or complex to be studied. The price for the high accuracy of crystallographic structures is that a good crystal must be found, and that limited information about the molecule's dynamic behavior in solution is available from one single diffraction experiment. "In the core regions of the molecules, X-ray and NMR structures agree very well, and enzymes maintain their activity even in crystals, which often requires the design of non-reactive substrates to study enzyme mechanisms." (Rupp, 2005)

Hodgkin's pioneering efforts in developing techniques for x-ray crystallography has resulted in the discovery of the molecular structure of penicillin, vitamin b-12 and insulin. More specifically, Hodgkin's pioneered efforts on developing a technique called protein crystallography. She is known as its founder. She and her mentor, J.D. Bernal, were the first to successfully apply X-ray diffraction to crystals of biological substances, beginning with pepsin in 1934.

As mentioned, Hodgkin's contributions to crystallography included solutions of the structures of cholesterol, lactoglobulin, ferritin, tobacco mosaic virus, penicillin, vitamin B-12, and insulin (a solution on which she worked for 34 years), as well as the development of methods for indexing and processing X-ray intensities.

After the work with Bernal, she established her own laboratory at Oxford, described in the memoirs of her many students as an "unfailingly joyful and productive environment." (Dodson, 1981)

In Hodgkin's career, the challenges were always huge. Every new technique seemed to reach limits that constrained the size of protein that could be successfully solved, and each protein tackled presented special problems of its own. Hodgkin was elected a Fellow of the Royal Society in 1947 after publishing the structure of penicillin and was awarded the Nobel Prize in Chemistry in 1964 for her solution of vitamin B-12. The solution of the insulin structure came in 1969, after many years of struggle.

Hodgkin and her collaborators produced a more refined solution in 1988, one that took full advantage of computational techniques that can now reduce the time for protein solutions from years to months or weeks.

These discoveries are important in today's world because it has greatly helped succeeding scientists in the design of drugs. These drugs have helped cure a wide variety of infections and diseases from ear infections, to sexually transmitted infections to the more serious necrotizing fasciitis.

Penicillin

Penicillin is a drug that is used as an antibiotic agent. Antibiotics are natural substances that are released by bacteria and fungi into their environment as a means of inhibiting other organisms. This drug is one of the earliest discovered and most widely used antibiotic agent today.

In history, penicillin has served to cure Allied Soldiers on D-Day. Today, penicillin is used to treat a wide variety of infections and diseases. It is used to treat ear infections, necrotizing fasciitis, some sexually transmitted infections such as syphilis, tonsillitis and wound botulism.

The work of Hodgkin on Penicillin is important to today's world. She used x-ray crystallography to find the structural layout of atoms and the overall molecular shape of penicillin. Her discovery of the molecular layout of penicillin helped other scientists to develop other antibiotics.

Vitamin B-12

One of Hodgkin's most important works was her determination of the molecular structure of Vitamin B-12. Again, this was done through her pioneering efforts in x-ray crystallography.

Her discovery is important to today's world. It has helped scientists who succeeded her study in developing