Biographical Memoirs Volume 86 (2005) / Chapter Skim
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Harry Beevers
Harry Beevers
Pages 16-35
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From page 17... ...
The most notable achievement of his research group was the discovery of the glyoxylate cycle in seedlings of plants that store fat in their seed and utilize this fat as a source of energy and for the production of glucose during early seedling growth. These studies culminated in the demonstration that the glyoxylate cycle of fat-storing seeds is located in a specific metabolic compartment, the glyoxysome.
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From page 18... ...
During his secondary education, Harry was inspired by David Hughes, a dynamic biology teacher who took his students on field trips to study the local ecology of the nearby moors and the relics of the Alpine flora in the Upper Teesdale.
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From page 19... ...
Determination of the respiratory quotient—the volume of CO2 released to the volume of O2 absorbed—of plant organs allowed plant physiologists to make certain deductions about the metabolic processes involved. With complete oxidation of hexose, the respiratory quotient (RQ)
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From page 20... ...
was known in his Welsh village as "Thomas the Book" because he wrote a classic textbook entitled Plant Physiology that saw five editions between 1935 and 1973. This book inspired generations of British and colonial students of plant biology.
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From page 21... ...
They found that the response of plant cells to weak acids increases when the incubation medium has a pH value below the pK of the weak acid (in other words, when the acid is protonated) and that the reverse held for weak bases, which were more active under mildly alkaline conditions.
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From page 22... ...
Having studied the entry of weak acids into plant cells, Harry lowered the pH of the incubation medium allowing malonate to enter the cells, and under those conditions respiration was inhibited. Pyruvate consumption in the TCA cycle was prevented, and pyruvate was diverted to ethanol.
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From page 23... ...
With labeled precursors Harry's group pioneered the demonstration of pools of metabolites later shown to be attributable to subcellular compartments in the plant cell. It was about this time that Harry decided to work on the conversion of fat to sugar in castor bean seedlings.
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From page 24... ...
According to Hans Kornberg, Harry met Hans Krebs socially at a college function and explained to him his interest in the conversion of fat to carbohydrate; Krebs then suggested that Harry should collaborate with Kornberg. This was the time when the glyoxylate cycle was being formulated in bacteria.
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From page 25... ...
The laboratories of Paul Stumpf and Harry Beevers discovered simultaneously that glyoxysomes contain the enzymes for the p-oxidative breakdown of fatty acids. Leaves had been shown to possess structurally similar organelles termed peroxisomes, and Edward Tolbert's laboratory discovered that these contain glycolate oxidase, an enzyme essential for photorespiration.
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From page 26... ...
That was also the year that Professor Kenneth Thimann, a member of the Academy, persuaded Harry to leave the shores of the Wabash and the weekly cheering of his favorite Boilermakers football team and join the biology faculty of the new campus of the University of California, Santa Cruz. Harry and Jean packed their bags once more and departed for the redwoods.
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From page 27... ...
Resolving this question required the use of biochemical techniques as well as immunocytochemistry to study the enzymic complement of both peroxisomes and glyoxysomes in greater detail, work carried out by Anthony Huang, Roland Theimer, and Takashi Kagawa in Harry's laboratory. MORE METABOLIC COMPARTMENTS: PLASTIDS AND VACUOLES Harry's interest in the subcellular compartments that contribute to the conversion of fat to carbohydrate led him to study the role of both plastids and vacuoles in this process.
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From page 28... ...
Another plant metabolism strand that runs through Harry's work in the 1970s concerns the biosynthesis of phospholipids and the relationship between the endoplasmic reticulum—the site of many lipid biosynthetic enzymes— and glyoxysome biogenesis. Electron micrographs of both plant and animal cells published at that time suggested that microbodies arose by budding the endoplasmic reticulum (ER)
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From page 29... ...
actions of plant cells, Harry used whole plants to refute the purported functions of plant transpiration. In a series of experiments Widmar Tanner and Harry demonstrated that illuminated whole corn plants under nontranspiring conditions did not overheat and die and still took up and transported mineral nutrients.
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From page 30... ...
Notable in this regard is that he was elected presi
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From page 31... ...
In 1970 the society awarded Harry its highest honor, the Stephen Hales Prize, "in recognition of his outstanding studies of glyoxylate metabolism and glyoxysomes." ACKNOWLEDGMENTS AND NOTES I knew Harry quite well, but I could not have written this piece without the information supplied by quite a few of Harry's friends and collaborators, including David Walker, Hans Kornberg, Martin Gibbs, Widmar Tanner, Nick Kruger, Anthony Huang, Michael Lord, Takashi Akazawa, Mikio Nishimura, andJoe Chappell, and by Harry's brother Leonard and his UC Santa Cruz colleague Lincoln Taiz. Harry wrote a prefatory chapter published in the Ann ual Review of Plan t Physiology and Plant Molecular Biology (44[1993]
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From page 32... ...
7:267-298. 1957 The glyoxylate cycle as a stage in the conversion of fat to carbohydrate in castor beans.
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From page 33... ...
Association of the glyoxylate cycle enzymes in a novel subcellular particle from castor bean endosperm. Biochen`.
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From page 34... ...
Subcellular distribution of gluconeogenetic enzymes in germinating castor bean endosperm. Plant Physiol 64:31-37 Microbodies in higher plants.
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