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TAUBE LECTURE
The 2007 Taube Lecture took place on Thursday, December 6th. Our honored speaker was Professor Harry B. Gray of the Beckman Institute at the California Institute of Technology. You can read more about his lecture titled "The Currents of Life: Electron Flow through Proteins" below.
About the lecture: Aerobic respiration and photosynthesis work in concert: the oxygen that is evolved by photosynthetic organisms is the oxidant that sustains life in aerobic microbes and animals; and, in turn, the end products of aerobic respiratory metabolism, carbon dioxide and water, nourish photosynthetic organisms. Electron flow through proteins and protein assemblies in the respiratory and photosynthetic machinery commonly occurs between metal-containing cofactors that are separated by large molecular distances, often in the 10-25 angstrom range. Although these cofactors are weakly coupled electronically, the reactions are remarkably rapid and specific. Understanding the underlying physics and chemistry of these distant electron transfer processes is the goal of the experimental work in my laboratory. We have investigated free energy, temperature, and distance dependences of electron transfer rates in Ru(diimine)-modified iron and copper proteins. Employing laser flash/quench triggering methods, we have shown that 20-angstrom, coupling-limited Fe(II) to Ru(III) and Cu(I) to Ru(III) electron tunneling can occur on the microsecond timescale both in solutions and crystals; and, further, that analysis of these rates suggests that distant donor-acceptor electronic couplings are mediated by a combination of sigma and hydrogen bonds in folded polypeptide structures. In recent work, we have found that 20-angstrom hole hopping through intervening tryptophan residues is several hundred-fold faster than single-step electron tunneling in Re-modified copper proteins. Lessons learned about the control of electron tunneling and hopping are now being used to design sensitizer-modified protein machines incorporating catalysts that can generate hydrogen fuel from sunlight and water. 1. Gray, H. B. & Winkler, J. R. (2003). Electron tunneling through proteins. Quart. Rev. Biophys. 36, 341-372. 2. Gray, H. B. & Winkler, J. R. (2005). Long-range electron transfer. Proc. Natl. Acad. Sci. USA 102, 3534-3539. About Professor Gray: Harry Barkus Gray is the Arnold O. Beckman Professor of Chemistry and the Founding Director of the Beckman Institute at the California Institute of Technology. His main research interests center on inorganic spectroscopy, photochemistry, and bioinorganic chemistry, with emphasis on understanding electron transfer in proteins. For his contributions to chemistry, which include over 700 papers and 17 books, he has received the National Medal of Science from President Ronald Reagan (1986); the Linderstrøm-Lang Prize (1991); the Basolo Medal (1994); the Gibbs Medal (1994); the Chandler Medal (1999); the Harvey Prize (2000); the Nichols Medal (2003); the National Academy of Sciences Award in Chemical Sciences (2003); the Benjamin Franklin Medal in Chemistry (2004); the Wolf Prize in Chemistry (2004); the City of Florence Prize in Molecular Sciences (2006); six national awards from the American Chemical Society, including the Priestley Medal (1991); and 16 honorary doctorates. He is a member of the National Academy of Sciences; the American Academy of Arts and Sciences; the American Philosophical Society; an honorary member of the Italian Chemical Society; a foreign member of the Royal Danish Academy of Sciences and Letters; the Royal Swedish Academy of Sciences; and the Royal Society of Great Britain. He was California Scientist of the Year in 1988. He has served as a Member of the Board of Directors of the Arnold and Mabel Beckman Foundation since 1994. About the Taube Lecture Series: The Taube Lecture Series was created in honor of the work of Henry Taube, the Marguerite Blake Wilbur Professor of Chemistry, Emeritus, and recipient of the 1983 Nobel Prize in chemistry. A member of the Stanford faculty since 1962, Taube was "one of the most creative contemporary workers in inorganic chemistry," according to the Royal Swedish Academy of Sciences, which awarded him the Nobel Prize for his insights into how electrons are transferred from one molecule to another during chemical reactions. "Henry was a scientist's scientist and a dominant figure in the field of inorganic chemistry," said friend and collaborator Jim Collman, professor emeritus of chemistry at Stanford. "I knew him for 40 years. He was an unparalleled personality and really had no counterparts." Born in Neudorf, Saskatchewan, Canada, on Nov. 30, 1915, Taube attended the University of Saskatchewan, earning a bachelor of science degree in 1935 and a master of science in 1937. He received a doctorate from the University of California-Berkeley in 1940 and was an instructor there from 1940-41. "I became deeply interested in chemistry soon after I came to Berkeley," Taube recalled. "Just the general atmosphere of the college was conducive of this; chemistry was in the air. There was little pretense [among the faculty] and they didn't feel that they had to impress others. At any rate, the fire was lit there quite early in my stay." He joined the Cornell University faculty in 1941, becoming a naturalized United States citizen in 1942, and then moved in 1946 to the University of Chicago where he remained until 1961. A year later he joined the Stanford faculty as professor of chemistry, a position he held until 1986, when he became professor emeritus. Taube served two stints as chair of Stanford's Department of Chemistry—from 1972-74 and 1978-79—and continued doing experimental work at Stanford until his death in 2005. Past Taube lecturers include: Henry Taube Richard H. Holm Kenneth N. Raymond James Collman
Questions: Please contact Patricia Dwyer at 650-723-4770.
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