Harry Gray wins Wolf Prize

Harry Gray still recalls the day in 1982 when, after eight years of research, he and his colleagues finally proved that electrons can literally jump from one molecule to another. “I was ecstatic,” recalls the Caltech chemist. “My whole research group was ecstatic.” Gray is referring to electron transfer (ET), the process of moving an electron from one place to another, which is critical for life.

For his insight into ET, Gray, Caltech’s Beckman Professor of Chemistry and founding director of the Beckman Institute, has been awarded the 2004 Wolf Prize in Chemistry. Specifically, the Wolf Foundation is honoring Gray for his “pioneering work in bio-inorganic chemistry, unraveling novel principles of structure and long-range electron transfer in proteins.” The prize includes an honorarium of $100,000.

“It is really special to be recognized for experimental work that’s been done with students and other good friends,” says Gray. “It has been so much fun.”

Electron-transfer reactions are ubiquitous in the chemistry of biological systems. They are fundamental processes that, among other functions, are responsible for the generation of energy in a cell.

Gray studies the tiny bits of inorganic material in living molecules, such as iron or copper, which, within proteins, have long been known to transfer electrons. But conventional wisdom held that in order for such exchanges to take place, the molecules had to be physically close enough to interact. The puzzle was how the few metal atoms in proteins, surrounded by thousands of other atoms, could maneuver close enough for the exchange. Further, in biological systems the timing always has to be perfect in order to allow for such things as breaking down food and generating energy, conducting photosynthesis, or fixing nitrogen.

The answer, Gray and his colleagues discovered, is that in biological systems, electrons really do jump, and jump big—his work shows that electrons can leap across at least 30 atoms in a large protein molecule in less than one-millionth of a second.

Gray’s insights could have practical applications in a number of areas. Because ET plays a role in the body’s natural barriers against foreign substances, his work may influence the design of drugs to get around those barriers. It also has implications for computer miniaturization, energy storage, and the effort to develop an artificial counterpart to photosynthesis.

Gray, a Caltech professor since 1966, is the recipient of numerous distinguished honors and awards. These include the National Medal of Science in 1986 and six national awards from the American Chemical Society, including the Priestley Medal, the society’s highest honor. Last year he received both the National Academy of Sciences Award in Chemical Sciences and an honorary degree from the University of Copenhagen that included an audience with Queen Margrethe II of Denmark.

The Wolf Prize was established in 1978 and is designed to promote science and art for the benefit of mankind. In presenting Gray the prize, the foundation noted that “his ingenious chemistry, meticulously executed, has given us a real understanding, for the first time, of a biological process of great significance for life.”
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