Biographical Memoirs Volume 84 (2004) / Chapter Skim
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Pages 113-146
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From page 113... ...
They were his educational experiences at New York University and at Cambridge; his return to the United States to begin his American career for one year at Harvard; his first academic appointment at Columbia College of Physicians and Surgeons in New York City; and finally his selection as codirector of the Institute for Enzyme Research at the University of Wisconsin at Madison, where he remained until his untimely death in 1983. As we will see, Green played a pivotal role in the expanding 113
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From page 114... ...
114 B I O G R A P H I C A L M E M O I R S frontier of enzymology, not only in the United States but also throughout the world. David Ezra Green was born in Brooklyn, New York, on August 5, 1910.
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From page 115... ...
D A V I D E Z R A G R E E N 115 University and left for Cambridge University in England, where his potential talents were nurtured in the fertile soil of the Biochemistry Department led by the famous Sir Frederick Gowland Hopkins. The department was home to some of the greatest biochemists of that period -- including David Keilin, Malcolm Dixon, Robin Hill, Joseph and Dorothy Needham, Judah Quastel, Marjorie Stephenson, Ernest Gale, and Norman Pirie -- and was ranked as one of the leading centers of innovative research in the new field of enzymology.
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From page 116... ...
. One may ask with good reason what is the point of imitating the cell with mixtures of the components in test tubes.
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Baird Hastings, at that time the chair of the Department of Biological Chemistry at the Harvard Medical School in Brookline. At the appointed hour, I was ushered into the august and wood-paneled chambers of Hastings and after a brief series of questions, Hastings informed me that he was no longer active in this field but that a "young chap" just back from Cambridge University was downstairs and it would be a worthwhile experience for me to at least meet him.
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From page 118... ...
Nevertheless this thesis influenced the directions many biochemists took in their researches in the late 1940s and throughout the 1950s. Late in 1941 Green was appointed assistant professor of biochemistry in the Department of Medicine at the Columbia College of Physicians and Surgeons in New York City.
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From page 119... ...
His research team published 20 papers on the enzymatic oxidation of amino acids, transamination, and the mechanism of pyruvic acid oxidation. In addition, he supported the construction of an ultrasonic device that was used to disintegrate bacteria, purchased one of the first battery-driven Beckman DU spectrophotometers, and was one of the first biochemists to use the new Waring blender to extract enzymes from tissues.
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From page 120... ...
In his last few years at Columbia Green was so successful in isolating and purifying soluble enzymes that he became bored with his successes and expanded his interests into the far more complicated and challenging field of oxidative phosphorylation and into multi-enzyme systems, such as those involved in the complete oxidation of pyruvic acid. For these studies Green used insoluble preparations obtained each day from rabbit kidneys and named this complex mixture of enzyme-bound systems the "cyclophorase system." Many rabbits were needed to keep a supply of fresh kidneys for this work.
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From page 121... ...
From his arrival in Madison in 1948 until his death in 1983 Green and his colleagues engaged in six areas of research: fatty acid oxidation; metallo-flavoproteins; fatty acid synthesis; mitochondria, coenzyme Q, and the respiratory chain complexes; mitochondrial anatomy; and electron transport and oxidative phosphorylation. These areas represent unique chapters in Green's work at the Institute for Enzyme Research.
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From page 122... ...
He was able to equip his laboratory in the new Institute for Enzyme Research building in a grand way, which was unique for those days, and support 10 postdoctoral fellows. Green's reputation attracted many eager young scientists to the Institute for Enzyme Research, including two of us (H.B.
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From page 123... ...
The continual presence of such scientists and the ideas and expertise they brought to the Institute for Enzyme Research made it an interesting and stimulating place to be. Green once said during those days, "If we can lick fatty acid oxidation, I will be the happiest of men." This meant that those who worked most closely with him were involved in this project.
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From page 124... ...
Some additional hurdles had to be overcome, however, before the individual activities could be separated. Relying on his experience with enzymes and his knowledge of how to link them in ways that would not interfere with the reaction that was to be measured, Green devised a quick and practical assay for the overall fatty acid oxidation activity.
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From page 125... ...
To be able to turn over fatty acid oxidation the assay also had to contain malate dehydrogenase, oxaloacetate-condensing enzyme, diaphorase, CoA, ATP, NAD, and a linking dye, such as pyocyanin. All of the ingredients needed for Green's assay could be prepared or purchased, except for CoA, which was available only in minute amounts and had to be obtained from microbiologists who had extracted it in a crude form from bacteria.
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From page 126... ...
These were truly exciting days. Through the combined effort of at least half of the people in the Institute for Enzyme Research -- in producing the CoA derivatives, in purifying and characterizing the enzymes, and in making assays -- the entire work on the enzymes involved in fatty acid oxidation was completed in less than a year.
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From page 127... ...
. So it happened that Lynen was also invited to the 1953 spring meeting of the American Society for Biological Chemistry in Chicago to present a plenary lecture on fatty acid oxidation.
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From page 128... ...
Soon after the enzymes of fatty acid oxidation were characterized Green and many of the Institute for Enzyme Research fellows moved on to study the more challenging problem of electron transport and oxidative phosphorylation. Green gave Gibson and Wakil the task of "mopping up the field of fatty acid oxidation, and showing that fatty acid synthesis is the reversal of -oxidation." The idea that the processes of fatty acid synthesis and the beta-oxidation of fatty acids were interrelated was not new, having been articulated at the beginning of the twentieth century by F
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From page 129... ...
acetate into long-chain fatty acids. Ammonium sulfate fractionation of the soluble pigeon liver extracts yielded three separate protein fractions that collectively converted [14C]
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From page 130... ...
For instance, if the incubation of the reaction mixture was carried out in a conical test tube rather than in a round-bottom test tube, there was a significant increase in the incorporation of [14C] acetyl-CoA into fatty acids, a phenomenon that was called the "test tube factor." If the incubation mixture was placed in a shaking bath at 37°C, there was a relative decrease in fatty acid synthesis.
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From page 131... ...
inhibited fatty acid synthesis. Treating avidin with free biotin before allowing it to interact with the acetyl-CoA carboxylase did not inhibit the enzyme, and its product malonylCoA was readily formed and was converted in the presence of NADPH into the long-chain fatty acids, myristate, palmitate, and stearate by the second highly purified protein fraction (R2g)
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From page 132... ...
After his success with the fatty acid oxidation system Green set out to isolate and describe the components of the mitochondrial respiratory chain and to determine how mitochondria produce energy by oxidative phosphorylation. While soluble preparations of succinate and NADH dehydrogenases, and cytochrome C were available, the link between these components was missing.
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From page 133... ...
In the years that followed the fatty acid blitzkrieg the Institute for Enzyme Research grew and its organizational structure changed. As Green added a number of capable lieutenants his more direct involvement, which had been considerable during the fatty acid project, became noticeably diminished.
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From page 134... ...
that were derived from mitochondria. Without this discovery, progress on the electron transport chain would have been severely hampered.
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From page 135... ...
Nevertheless investigators at the Institute for Enzyme Research, and independently Hackenbrock, were the first to observe the transition between the orthodox and condensed conformation of mitochondria. More significantly three of Green's postdoctoral fellows-Douglas Hunter, Robert Haworth, and James Southard-studied the relationship between configuration, function, and permeability in calcium-treated mitochondria and concluded that "mitochondria have a built-in mechanism which responds to low levels of calcium, phosphate, and fatty acids, resulting in simultaneous changes, including increased permeability, induction of ATPase, uncoupling of oxidative phosphorylation, and loss of respiratory control." These observations are considered today by many scientists to rep
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From page 136... ...
The scientific record now includes a large number of highresolution protein structures that show the actual electron carriers and proton channels in mitochondria, well-founded and experimentally supported theories of electron transfer through peptide chains, and knowledge of electron and hydrogen tunneling. Nevertheless Green did not subscribe to a 1970s theory that has stood the test of time: Peter Mitchell's chemiosmotic theory.
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From page 137... ...
As his fame spread throughout the United States immediately after World War II he attracted many junior collaborators both at Columbia University and later at the Institute for Enzyme Research. He took an active interest in his junior colleagues, not only by encouraging and inspiring them but also by allowing them to develop their own independent careers.
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From page 138... ...
In 1977 a symposium was held in New Orleans to honor Green's sixty-seventh birthday. His former colleagues Sidney Fleischer, Joe Hatefi, David McLennan, and Alex Tzagoloff organized the symposium under the theme "The Molecular Biology of Membranes," and many other former colleagues were present to give honor to Green as the scholar and the innovative scientist that he was.
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From page 139... ...
WE WISH TO THANKProfessor Rowena Matthews, Green's eldest daughter, and his granddaughter, Congresswoman Tammy Baldwin, for their valuable input into the writing of this biographical memoir, and Professor Frank Huennekens and Youssef Hatefi for the background information on the Institute for Enzyme Research. We especially thank H
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From page 140... ...
In Perspectives in Biochemistry: Thirty-One Essays Presented to Sir Frederick Gowland Hopkins by Past and Present Members of his Laboratory, eds.
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From page 141... ...
210:149-64. Fatty acid oxidation in soluble systems of animal tissues.
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From page 142... ...
Biosynthesis of fatty acids by soluble enzyme fractions. Biochim.
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From page 143... ...
Studies on the mechanism of fatty acid synthesis V Bicarbonate requirement for the synthe sis of long-chain fatty acids.
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From page 144... ...
VII. Biosynthesis of fatty acids from malonyl CoA.
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