GREEN, DAVID EZRA

(b. Brooklyn, New York, 5 August 1910; d. Madison, Wisconsin, 8 July 1983),

biochemistry, enzymology.

Green was a biochemist who, early in his career, made substantial contributions to the identification and characterization of soluble enzymes responsible for biological activities. Later in his career he established a laboratory that made major discoveries about complex cellular oxidation systems. As time advanced, Green became ever more theoretical and speculative in his own work, while supporting postdoctoral fellows who made important empirical discoveries in biochemistry.

Early Life and Education . Green’s parents were Hyman Levy Green, a garment manufacturer (he later managed the Harwood Factory in Marion, Virginia), and Rose Marrow Green. David Green was born on 5 August 1910 in Brooklyn, New York, where he attended public grade and high schools in Brooklyn. He initially intended to prepare for medical school and pursued a premedical curriculum for two years at New York University (NYU), beginning in 1928. Having been offered a student assistantship in the Biology Department, however, he shifted his efforts toward basic research. He was awarded a bachelor’s degree in biology in 1931 and a master’s degree the following year, both at NYU. Green spent the summers of 1930, 1931, and 1932 at the Marine Biological Laboratory at Woods Hole, Massachusetts, working with NYU professor Robert Chambers and Leonor Michaelis. Michaelis in particular helped inspire Green’s subsequent interest in biological oxidations.

After completing his master’s degree, Green went to Cambridge University in England, where Frederick Gow-land Hopkins directed a world-renowned center of biochemical research that employed Malcolm Dixon, David Keilin, Joseph and Dorothy Needham, Judah Quastel, and Marjorie Stephenson, among others. Together, they pioneered in the quest to identify the enzymes responsible for a host of physiological processes. In his initial year, working in the laboratory of Dixon, he conducted research on the reduction potentials of three metabolites: cysteine, glutathione, and glycylcysteine. This research resulted in his first paper, “The Reduction Potentials of Cysteine, Glutathione, and Glycylcysteine,” published in Biochemical Journal in 1933. It became the basis for his PhD, awarded the following year. Green remained at Cambridge for the rest of the decade, first as a Beit Memorial Fellow and later a Senior Beit Fellow, pursuing an ambitious agenda of research on soluble oxidative enzymes that culminated in thirty-two papers in peer-reviewed journals.

During his years at Cambridge University, Green met Doris Cribb, director of the design department at the Cambridge School of Art, whom he married on 16 April 1936. Their first daughter, Rowena, who became a distinguished biochemist herself, was born while the two lived in Cambridge.

At Harvard and Columbia . Although Green would have preferred to remain in England, the United States recalled all U.S. citizens living in Europe following the British defeat at Dunkirk in 1940. Green then had to scramble to find a suitable position in the United States, a challenge because enzymology had yet to develop as a major specialization in the United States. Initially, he accepted a position at Harvard Medical School in Cambridge, Massachusetts, as a research fellow in biochemistry. Despite Harvard’s overall prominence, the facilities available to Green were far inferior to those to which he was accustomed at Cambridge University, lacking a cold room, a centrifuge, and a Warburg constant volume respirometer system, equipment that had been crucial in his earlier research. Green, though, was able to procure a grant from the Ella Sachs Ploetz Foundation, enabling him to establish a small laboratory and to continue his research. During his year at Harvard he isolated a yeast flavoprotein (“A Flavoprotein from Yeast,” 1941) and purified potato starch phosphorylase (“Starch Phosphorylase of Potato,” 1942), results which he published in the Journal of Biological Chemistry.

Green’s focus was not only on obtaining new results himself but on giving focus to the field of enzymology. Part of his effort was directed to writing Mechanisms of Biological Oxidation, published in 1940, in which he attempted to synthesize what was then known about enzyme systems figuring in biological oxidations. He also contributed an essay, “Enzymes and Trace Substances” (1941), to the first volume of the new annual series Advances in Enzymology, in which he proposed the thesis that any substance required in trace amounts in the diet must be part of an enzyme. This book and paper proved extremely influential in enticing researchers, especially in the United States, into the field of enzymology.

In 1941 Green was appointed instructor in biochemistry in the College of Physicians and Surgeons at Columbia University, where he remained until 1948. Green’s modest two-room laboratory became a focus of interactions with many of the major emerging biochemists in the United States, including Fritz Lipmann, Herman Kalckar, David Nachmanson, Severo Ochoa, and Efraim Racker. During this period Green organized the Enzyme Club, which held monthly meetings at the faculty club at Columbia University. These gatherings provided a stimulating forum for investigators drawn to the study of enzymes and the prospects for explaining biological reactions in terms of enzymes.

While at Columbia, Green not only pursued research on the enzymes involved in the oxidation of amino acids, the mechanism of pyruvic acid oxidation, and transami-nation, but also participated in the development of a new instrument, an ultrasonic device to disintegrate bacteria, and pioneered in the application of the Waring blender to extract enzymes from tissues and the battery-driven Beckman DU spectrophotometer. Green’s focus during this period turned increasingly to the recently characterized phenomenon of oxidative phosphorylation, and especially to the complex of reactions involved in the complete oxidation of pyruvic acid to carbon dioxide and water. In the 1930s David Keilin, a member of the research group at Cambridge University, had identified cytochromes as reversibly oxidizable components of living cells and had begun to ascertain how they were sequenced to constitute an electron transport chain. When he and Edward Hartree had tried to isolate the enzymes during the 1940s, they found that any preparation which retained the capacity to carry out oxidative phosphorylation retained cell particulates. They interpreted this finding, which many biochemists regarded as a nuisance, as showing that the respiratory reactions were somehow linked to the physical-chemical structure of the cell.

Cyclophorase Proposal . Green set out to study the complete oxidation of pyruvic acid to carbon dioxide and water employing a preparation from rabbit kidney. The preparation was complex, requiring homogenation with potassium chloride using alkali to neutralize the acid that formed, followed by multiple resuspensions in saline and centrifugation. His first goal was to isolate, through fractionation of the preparation, the enzyme responsible for catalyzing pyruvic to acetic acid. But any preparation that reacted with pyruvic acid performed the entire set of reactions resulting in carbon dioxide and water. From these studies, Green became convinced that the insoluble character of the enzymes pointed to the fact that they were bound into a unit, which he designated the “cyclophorase system.” By referring to a cyclophorase system, he meant to contrast the enzymes involved in aerobic respiration with those involved in other biochemical processes such as glycolysis, purine synthesis, and the pentose and urea cycles. In those cases the enzymes can be isolated and an operative system reconstituted from the isolated components. He explained the term cyclophorase as “literally meaning the system of enzymes carrying through the (citric acid) cycle” (Green, 1951b, p. 17). Green acknowledged that the ending “ase” is usually applied to individual enzymes, but cited precedent for his extension to a “team of enzymes”: “Keilin and his school have been referring for more than two decades to the succinic oxidase and cytochrome oxidase systems. Neither the one nor the other represents a single enzyme. They represent a considerable group of enzymes all of which are associated with the same particulate elements” (Green, 1951b, pp. 17–18).

Green conceptualized the cyclophorase system as involving a precise physical arrangement that would facilitate cooperative action between spatially proximal enzymes. He also maintained that this arrangement would enable the components to behave in ways they could not otherwise: “The chemical organization by which the many constituent enzymes are integrated confers properties on the various enzymes which they may not necessarily enjoy when separated from the complex and isolated as single enzymes” (Green, 1951b, p. 18). At the time, Green claimed that the cyclophorase system represented a newly discovered constituent of the cell.

Most biochemists reacted to Green’s cyclophorase proposal with extreme skepticism. In part this was due to Green’s introduction of a new name and his often-poetical accounts of the proposed system, whereas many found the particulate nature of any preparation capable of performing oxidative phosphorylation as a challenge to be overcome. In part this negative response was also due to the fact that whereas Green had been a master in the techniques required to isolate and study single enzymes, his procedures for preparing the cyclophorase system were regarded as less precise. Green himself made efforts to relate his proposal to the research of other biochemists. At the same time as he was first formulating his cyclophorase proposal, a group of researchers at the Rockefeller Institute was analyzing the chemical composition of the four fractions that Albert Claude had isolated from mammalian liver cells through centrifugation. The team, led by George Hogeboom, determined that most of the capacity to oxidize cytochrome c and succinic acid was due to what Claude had termed the large granule fraction and which the team now determined to originate from mitochondria. Claude himself designated the mitochondrion as the power plant of the cell, and soon other researchers, such as Albert Lehninger, localized other oxidative systems, like that responsible for fatty acid metabolism in the mitochondrion, as well. Although at first resistant to the claim that these oxidative systems were localized in a known cell organelle, Green eventually linked his cyclophorase system with the mitochondrion, crediting John W. Harman, who was working with him, with establishing in 1950 the proportionality of cyclophorase activity and the presence and number of mitochondria. He continued to insist, however, in using the term cyclophorase system “for the functional attributes of the same entity” (Green, 1951b, p. 19, n. 2). Green failed, however, to convince other biochemists to adopt the term cyclophorase, and many remained extremely skeptical of his emphasis on systems or teams of enzymes.

Green was not dissuaded, and he began to propose an even more elaborate scheme in which the cyclophorase system not only linked together the enzymes, but also bound them to the coenzymes that figured in the reactions. Washing the preparation would remove the coenzymes and, as well, most of the NAD, NADP, FAD, and ATP in the cell that was normally bound in the cyclophorase system. Green proposed further that a co-enzyme was bound as a prosthetic group to the protein component of an enzyme, which he referred to as the apoenzyme, and that when the two were split, the enzyme was modified. Green suggested that such an arrangement was most efficient because it required only one coenzyme molecule per enzyme molecule, whereas if they were dissociated and relied on random processes such as diffusion to encounter each other, many times more coenzyme molecules would be required. Green, however, noted a serious problem posed by binding of the coenzyme to the enzyme:

Pyridinenucleotide must be capable not only of being reducible by the substrate of the oxidase with which the former is combined but also in its reduced form has to interact with the flavin prosthetic group of diaphorase—the enzyme that catalyzes the oxidation of dihydropyridinenucleotide by one of the cytochrome components. When the pyridinenucleotide is free as in the case of the classical, soluble systems, this sequence of reactions poses no difficulty. The co-enzyme is free to shuttle back and forth...... In the cyclophorase system with bound pyridinenucleotide, the extent of shifting back and form is severely limited. Some mechanism must be invoked to explain how a coenzyme fixed in a rigid structure would be capable of interacting with a variety of systems. (Green, 1951b, p. 429)

Establishing the Enzyme Institute . While Green had found little knowledge or interest in enzymes at Harvard and only emerging interest in New York, there was a location in the United States where appreciation and empirical study of enzyme systems was well advanced. This was the University of Wisconsin, where Conrad Elvehjem had carried out pioneering work identifying precursors of respiratory coenzymes such as nicotinic acid with vitamin B₃, crucial for preventing black tongue in dogs and pellagra in humans. Wisconsin had also recruited a substantial number of already well-established researchers investigating enzymes, including Van R. Potter, who was studying respiratory enzyme systems in cancer cells; Perry Wilson, who was studying processes of nitrogen fixation; and many promising investigators in the early stages of their careers. As the University of Wisconsin developed plans for a new enzyme institute, they initiated efforts to recruit Green.

The idea of establishing a postdoctoral research training center in enzymology in the United States appears to have emerged first at the Conference on Intracellular Enzymes of Normal and Malignant Tissues in Hershey, Pennsylvania, in the fall of 1945, a conference devoted to basic research concerning cancer. Major pioneering work in enzyme chemistry had been carried out by Otto Warburg, Otto Meyerhof, and Gustav Embden at research centers in Germany that had been closed by World War II. Hopkins’s laboratory at Cambridge University was the premier site for enzyme research in the English-speaking world, but it too had been severely impacted by the demands of the war. Recognizing the demise of the major training centers in Europe, Charles Glen King, scientific director of the Nutrition Foundation, approached Harry M. Miller of the Rockefeller Foundation, who in turn presented the idea of developing a center in the United States to Warren Weaver, director of the natural sciences at the Rockefeller Foundation. King identified the University of Wisconsin as offering the best foundation for establishing an institute for studying enzymes, noting the presence there of Elvehjem and Potter. In addition, beginning in 1938 the university had published a handbook on respiratory enzymes and another on methods of enzyme research; it had also hosted an international symposium on enzymes. The idea fell on very sympathetic ears as Weaver had just completed an assessment in which outside reviewers had examined the Rockefeller Foundation’s activities in the natural sciences and had targeted enzyme chemistry as a potent field for future investment. Weaver asked King for names of leaders in the field of enzymology, and Green was one of the eight King supplied. Weaver also approached the University of Wisconsin, and by September 1946 a task force appointed by the university president had developed plans for an institute.

In the end, the university went forward with its plans for what became the Enzyme Institute with only modest support for equipment from the Rockefeller Foundation, and Green was recruited to head the first of what was envisaged as several research teams. His team focused on the separation and identification of enzymes. A second team, headed by Henry Lardy, already an assistant professor of biochemistry at the university, was established a couple years later.

Research at Wisconsin . Green arrived in Madison in early 1948, before the new facilities for the institute were finished. He resumed his research and assembled a team of investigators in an abandoned building on the engineering campus. Green restricted his team to postdoctoral fellows and visiting researchers and so was not engaged in either undergraduate or graduate training at Wisconsin. Focusing on his proposed cyclophorase system he, together with his new collaborators, attempted to render the preparations more soluble so as to separate individual components of the enzyme systems. This involved varying the pH and salt concentrations of the preparations as well as modifying the centrifugation regime.

In addition to the oxidation of pyruvic acid, Green began to focus on fatty acid metabolism. None of the preparations the team members developed was sufficiently active to merit further purification, but Henry Drysdale, a student in Lardy’s group, had found he could increase fatty acid metabolism in extracts from rat livers by beginning with an acetone powder of rat liver. Finding rat liver to be an unsuitable source for his fractionation studies, Green applied the acetone powder approach to liver, kidney, and heart tissues from pigs and cows that he obtained from local Oscar Meyer slaughterhouses. To assay for reactions involved in the oxidation of fatty acids, Green used triphenyl-tetrazolium as the final acceptor and developed an approach in which he measured the quantities of acyl-CoA (activated fatty acid) formed, the generation of a double bond in the fatty acid chain, the hydration of the double bond, the oxidation of hydroxyl-acyl-CoA to form keto-acyl-CoA, and the separation of keto-acyl-CoA into two acyl-CoA derivatives. Green determined that the preparation also had to contain malate dehydrogenase, oxaloacetate-condensing enzyme, diaphorase, CoA, ATP, NAD, and a dye such as pyocyanin. Procuring sufficient CoA (coenzyme A, only recently discovered by Fritz Lip-mann in 1945), was one of the major challenges confronting this project, since it was generally available only in minute quantities extracted from bacteria. In his laboratory, Helmut Beinert developed a procedure for procuring CoA that relied on glutathione with mercuric ions. Green organized a team of technicians to produce large quantities until he persuaded Pabst Laboratories to adopt his method in exchange for providing him a continual supply of CoA. With this assay system in place, Green and his collaborators succeeded in rapid order in identifying the enzymes required for fatty acid metabolism and presented their results at a meeting of the American Society of Biological Chemists in Chicago during 1953.

After his work on fatty acid oxidation, Green returned to the cyclophorase system. Accepting the identification of the cyclophorase system with the mitochondrion, he now set out to describe the components of that system. His strategy was to decompose the mitochondrion into subunits until he could carry out each reaction individually in a purified preparation. To do this Green, together with Fred Crane, developed a “factory” for the production of mitochondria from cow and pig heart and liver so as to have an abundance of material on which to conduct his studies. These preparations routinely damaged mitochondria, resulting in two classes of submitochondrial particles that were localized in what he referred to as “light” and “heavy” fractions. The main difference between the particles was that in oxidizing succinate, the light fraction lacked the capacity to synthesize ATP, while the heavy fraction retained that capacity. Both fractions, though, phosphorylated ATP when other citric acid cycle substrates were supplied. Green further divided the light fraction (after treating it with 15 percent alcohol) into subfractions, one of which carried out electron transport but not oxidative phosphorylation. (He referred to these as “electron transport particles,” or ETP.) Another fraction supported phosphorylation when oxidizing compounds other than succinate. (He termed these “phosphorylating electron transport particles,” or PETP.)

To understand the genesis of these particles, Green collaborated with electron microscopist Hans Ris, also at the University of Wisconsin. A few years before this another electron microscopist, George Palade, had discovered not only that the mitochondrion was enclosed by two layers of membrane, but that there were repeated infoldings of the inner membrane, creating was Palade labeled “cristae mitochondriales,” which projected into the interior of the mitochondrion. The micrographs of Green’s fractionated particles revealed open fragments of what were identified as mitochondrial cristae in the PETP and less functional closed fragments of cristae in the ETP particles. The researchers viewed these results as supporting Palade’s suggestion that the processes of oxidative phosphorylation were localized in the cristae.

Contributions of Collaborators . Many biochemists became increasingly skeptical of Green’s research during this period. His techniques for subfractionating mitochondria appeared to many as unprincipled and as generating artifacts. His theoretical interpretations, which continued to emphasize complexes of enzymes interacting, struck many as purely speculative. But while his own credibility was diminished, Green succeeded in attracting a large cadre of young researchers to the Enzyme Institute who generated results that were highly respected. For example, he assigned David Gibson and Salih Wakil to follow up his research on the oxidation of fatty acids. In particular, they set out to show experimentally that, as was widely believed, the synthesis of fatty acids involved reversing the steps in fatty acid oxidation. They developed a preparation composed of three fractions from pigeon liver extracts that would convert labeled acetate into long-chain fatty acids when ATP, isocitrate, NADPH, and Mn were supplied. Wakil identified two protein fractions, one of which, acetyl-CoA carboxylase, in the presence of acetyl-CoA, ATP, and Mn⁺⁺, produced malonyl-CoA, which could then be made into fatty acids by the second protein fraction. Acetyl-CoA carboxylase was determined by other researchers at Wisconsin to contain the vitamin biotin.

Another major contribution by researchers in Green’s laboratory was the discovery of coenzyme Q by Fred Crane, Youssef Hatefi, Robert L. Lester, and Carl Widmer. These researchers found a lipid-soluble but water-insoluble factor that was required for the electron transfer from dehydrogenases to the electron transport system which had the properties of a quinone. (It was later found to be identical to ubiquinone, discovered by Richard A. Morton in 1955 and named “ubiquinone” because of its ubiquity.) After Crane left for a faculty position elsewhere, Hatefi collaborated with Daniel Ziegler in developing subfractions of mitochondria that would carry out the reactions of different parts of the electron transport chain. They were led to characterize four complexes of cytochromes and other constituents:

1. an NADH-ubiquinone reductase complex that included FMN and nonheme iron;
2. a succinate-ubiquinone reductase complex that included FAD and nonheme iron;
3. a ubiquinol-cytochrome c reductase complex that included cytochromes b and c₁,, and a nonheme iron protein; and
4. a cytochrome c oxidase complex that included cytochrome a and copper.

Thereafter, four of Green’s collaborators—Hatefi, A.

G. Haavik, L. R. Fowler, and David E. Griffiths (1962)— succeeded in reconstituting two systems: one capable of oxidizing NADH to carbon dioxide and water by combining complexes 1, 3, 4, and another capable of oxidizing succinate to carbon dioxide and water by combining complexes 2, 3, and 4. Both reconstitutions revealed particulate structures, suggesting that the respiratory chain was formed into a fixed assembly electron transfer system (one in which the molecules were in advantageous spatial relations for passing electrons sequentially from molecule to molecule).

At this point Green sought out another collaboration with an electron microscopist, this time Humberto Fernández-Morán at the University of Chicago. He had developed a technique for negative staining specimens with substances such as phosphotungstate or uranyl acetate that are electron dense but chemically inert. These substances do not react with membrane material, which then appears light against the dark background created by the electron dense material. With this technique, in 1964 Fernández-Morán discovered small particles (70–90 Å in size) located on stalks about 50 Å in length projecting from the cristae into the inner mitochondrial milieu. While small, these particles are numerous (between ten thousand to one hundred thousand per mitochondrion). When he applied the negative stains without prior fixation, mitochondria swelled and burst, extruding membranous material in the form of sheets, tubules, or ribbons that were studded with small spherical knobs about 90Å in diameter.

Green seized upon Fernández-Morán’s discovery, naming the knobs “inner membrane spheres” and proposing that they constituted the complete system of enzymes for electron transport. Albert Lehninger, however, calculated that the weight of the respiratory assembly was between one and two orders of magnitude greater than that of these particles. Green was not fully dissuaded and proposed instead that the four different complexes of enzymes Hatefi and Ziegler had identified as involved in electron transport were distributed over the base membrane (complexes 1 and 2), the stalk (complex 3), and the spheres (complex 4) respectively. Although much of their analysis focused on the relative sizes of the stalk and spheres and the minimum sizes, based on molecular weight, of the enzyme complexes, ultimately the investigators appealed to “biochemical considerations” to defend this localization: “Complexes I and II must interact with DPNH and succinate, respectively, both of which are localized in the interior of the crista, whereas complex IV must interact with molecular oxygen which would be more readily available in the solution outside the crista rather than in its interior” (Green, Fernández-Morán et al., 1964, p. 95). Green’s speculations about the organization of complexes, however, was cut short by the determination by Efraim Racker and his colleagues that the spheres contained ATPase, not complexes of the electron transport chain.

Later Work and Recognition . Although Green’s early successes were built on his skill in isolating and characterizing individual enzymes, he exhibited far less technical skill in his subsequent work on complex systems of nonsoluble enzymes. Rather, he often seized upon a result and attempted to synthesize a theoretical account of possible biochemical mechanisms in living systems. In the process, he often presented his theoretical ideas in more popular forums such as Scientific American and monographs, thereby prompting even more skeptical responses from his peers in biochemistry. Even as his peers questioned his turn to speculative theorizing and model building, though, he succeeded in recruiting talented young researchers to his laboratory who rewarded him with a continued record of important empirical results.

Green received a number of prominent awards and honors during his life. He was most proud of being selected first as a Junior Beit Fellow and then as a Senior Beit Fellow while at Cambridge University. In 1946 he was the first recipient of the Paul-Lewis Award in Enzyme Chemistry of the Division of Biological Chemistry of the American Chemical Society, and in 1962 he was elected to the National Academy of Sciences. During the latter years of his career Green became less engaged in conducting his own experiments while still overseeing a productive laboratory. In his last years he suffered from lymphoma, and he died in Madison on 8 July 1983.

BIBLIOGRAPHY

The Rockefeller Foundation Archives Center has archival material on the establishment of the Enzyme Institute at theUniversity of Wisconsin and on David Green’s role in it. The institute itself has a complete compilation of Green’s papers. The obituary by Beinert, Stumpf, and Wakil (2003) in Biographical Memoirs (cited below) includes a complete listing of his publications.

WORKS BY GREEN

“The Reduction Potentials of Cysteine, Glutathione and Glycylcysteine.” Biochemical Journal 27 (1933): 678–689.

“Reconstruction of the Chemical Events in Living Cells.” In Perspectives in Biochemistry, edited by Joseph Needham and David E. Green. Cambridge, U.K.: Cambridge University Press, 1937.

Mechanisms of Biological Oxidations. Cambridge, U.K.: Cambridge University Press, 1940.

“Enzymes and Trace Substances.” In Advances in Enzymology, edited by F. F. Nord and C. H. Werkman. Vol. 1. New York: Interscience, 1941.

With Eugene Knox and Paul K. Stumpf. “A Flavoprotein from Yeast.” Journal of Biological Chemistry 138 (1941): 775–782.

With Paul K. Stumpf. “Starch Phosphorylase of Potato.” Journal of Biological Chemistry 142 (1942): 355–366.

With William F. Loomis and V. H. Auerbach. “Studies on the Cyclophorase System I.” Journal of Biological Chemistry 172 (1948): 389–402.

“Enzymes in Teams.” Scientific American 181 (1949): 48–50.

“The Cyclophorase System of Enzymes.” Biological Reviews 26 (1951a): 410–455.

“The Cyclophorase System.” In Enzymes and Enzyme Systems, edited by John T. Edsall. Cambridge, MA: Harvard University Press, 1951b.

With Helmut Beinert. “Biological Oxidations.” Annual Review of Biochemistry 24 (1955): 1–44.

“Studies in Organized Enzyme Systems.” Harvey Lectures53 (1957–1958): 177–227.

“Biological Oxidation.” Scientific American199, no. 1 (1958): 56–62.

With Daniel M. Ziegler, Anthony W. Linnane, C. M. S. Dass, et al. “Studies on the Electron Transport System: Correlation of the Morphology and Enzymic Properties of Mitochondrial and Sub-mitochondrial particles.” Biochimica et Biophysica Acta 28 (1958): 524–539.

“Electron Transport and Oxidative Phosphorylation.” Advances in Enzymology 21 (1959): 73–129.

With J. Jarnefelt. “Enzymes and Biological Organization.” Perspectives in Biology and Medicine 2 (1959): 163–184.

With Youssef Hatefi. “The Mitochondrion and Biochemical Machines.” Science 133 (1961): 13–19.

“Structure and Function of Subcellular Particles.” Comparative Biochemistry and Physiology 4 (1962): 81–122.

“The Mitochondrion.” Scientific American 210 (1964): 63–74.

With Humberto Fernández-Morán, T. Oda, and P. V. Blair. “A Macromolecular Repeating Unit of Mitochondrial Structure and Function: Correlated Electron Microscopic and Biochemical Studies of Isolated Mitochondria and Submitochondrial Particles of Beef Heart Muscle.” Journal of Cell Biology 22 (1964): 63–100.

“The Mitochondrial Electron-Transfer System.” In Comprehensive Biochemistry, edited by Marcel Florkin and Elmer H. Stotz. Vol. 14. Amsterdam: Elsevier, 1966.

With Harold Baum. Energy and the Mitochondrion. New York: Academic, 1970.

OTHER SOURCES

Beinert, Helmut, and Paul K. Stumpf. “David Green Obituary.” Trends in Biochemical Sciences 8 (1983): 434–436.

———, Paul K. Stumpf, and Salih J. Wakil. “David Ezra Green, 1910–1983.” Biographical Memoirs 84 (2003): 112–145.

Huennekens, Frank M. “David E. Green: A Personal Recollection.” Journal of Bioenergetics and Biomembranes 16 (1984): 315–319.

———. “Enzyme Institute Days.” In The Molecular Biology of Membranes, edited by S. Fleischer, Youssef Hatefi, David H. MacLenna, and Alexander Tzagoloff. New York: Plenum Press, 1978.

“Impressions of David E. Green by His Colleagues.” In The Molecular Biology of Membranes, edited by S. Fleischer, Youssef Hatefi, David H. MacLenna, and Alexander Tzagoloff. New York: Plenum Press, 1978.

“Impressions of David E. Green by His Colleagues.” In The Molecular Biology of Membranes, edited by S. Fleischer, Youssef Hatefi, David H. MacLenna, and Alexander Tzagoloff. New York: Plenum Press, 1978.

William Bechtel