Biographical Memoirs Volume 50 (1979) / Chapter Skim
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William Zev Hassid
William Zev Hassid
Pages 196-231
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From page 197... ...
Russian and Yiddish were Zev's native languages. Little is known about his early education except that he was required to study traditional Jewish religious material.
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From page 198... ...
The curriculum included Hebrew, French, and Arabic languages, Hebrew religious studies, history, geography, and considerable science, plus professional studies in soil, plant nutrition, subtropical horticulture, animal husbandry, laboratory practice in analytical methods, and field experience in agricultural techniques. He graduated in 1916.
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From page 199... ...
When Hassid completed his military service with the rank of corporal in August 1920, he was awarded the British War Medal and the Victory Medal, bearing the inscription, "The great war for civilization." His superior officer provided him with the following recommendation: "Corporal Hassid has been employed as a clerk in the Battalion Orderly Room and at Records, 3rd Echelon. He is a conscientious, painstaking worker, reliable and capable, and as a soldier has borne an exemplary character." After leaving the army, Hassict decided to use the accumulated savings from his pay to go to California to study agronomy at the University, with the intention of returning ultimately to Palestine to assist in the development of scientific agriculture.
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From page 200... ...
Following graduation, he immediately started graduate studies in the School of Education, and in December 1926 he received a Certificate of Completion with majors in chemistry and general literature and minors in mathematics and physics. In the same month Hassid obtained a General Secondary School Credential from the State Board of Education, but he never taught in public schools.
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From page 201... ...
D Stewart of the chemistry department, a member of the thesis committee, was particularly impressed by the clear results and logical presentation of Hassid's thesis, and his enthusiastic reaction helped Hassid to obtain an appointment the following year as a Junior Chemist in the Division of Plant Nutrition of the Agricultural Experiment Station.
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From page 202... ...
as a major component of this plant extract and observed that reducing sugars were notably absent from acid hydrolysates. He then purified and characterized an abundant polysaccharide from the same organism and showed it to be a sulfated polygalactan.
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From page 203... ...
undertook the structural analysis of the biosynthetic product and showed that it had starchlike properties but that the molecules were unbranched in contrast to the highly branched natural polymer. In a short review for Chronica Botanica published in 1942, Hassid related the prevalent view that "the enzyme phosphorylase, and not amylase as had been previously assumed, is chiefly responsible for the synthesis and breakdown of starch in the plant." McCready and Hassid developed a convenient method for prepar
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From page 204... ...
In an extension of this work, the green alga Chlorella pyrenoidosa was utilized in place of barley leaves, allowing a much more efficient incorporation of the radiocarbon label. Studies of the kinetics of incorporation in the light and dark, and on the reversibility of the reaction, were carried out with Ruben and Kamen (1940~.
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From page 205... ...
Hassid's initial appointment as a Junior Chemist in the Agricultural Experiment Station was followed by promotion to the academic staff as an Instructor in Plant Nutrition (1939) and as Assistant Professor in 1941.
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From page 206... ...
Unfortunately, Professor Hoagland was pessimistic about the possibility of sweetening Coca-Cola by this method, and so further support of research of sucrose phosphorylase was left to the University and the U.S. Public Health Service.
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From page 207... ...
of uridine diphosphate D-glucose and the demonstration that this substance served as a glucosyl donor for synthesis of disaccharides focused attention on the sugar nucleotides as intermediates in the interconversion of carbohydrates, and Hassid directed his concern to these substances in higher plants. With Ginsburg and Stumpf (1956)
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From page 208... ...
, whereas the guanosine diphosphate derivatives of ~-galactose and D-mannose later were identified in the red alga Porphyra perforate (with I
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From page 209... ...
also made the important observation that mammary tissue contained an enzyme activity that transfers D-galactose to N-acetyl-D-glucosamine. Noting the occurrence in milk of oligosaccharides that contained this lactosamine unit, and finding that different mammary gland preparations gave different relative amounts of ~4C-lactose and N-acetyl-~4C-lactosamine when incubated with uridine diphosphate i4C-D-galactose, they concluded that "different enzymes are responsible for the synthesis of the two compounds." This conclusion, and a later one by Helene Babad and Hassid (1966)
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From page 210... ...
His earliest experiments dealt with the infiltration of radiocarbonlabeled sugars into plant leaves, but later they became more sophisticated with the utilization of well-defined sugar nucleotides as specific donors in cell-free enzyme systems. It was known that uridine diphosphate D-glucose was a precursor of a ,B-1~4glucan in ~cetobacter xylinum (L.
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From page 211... ...
A Barber, and Hassid reported the formation of cellulose from guanosine diphosphate D-glucose and a particulate enzyme preparation from mung bean seedlings.
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From this brief survey, we can see that there were few features of carbohydrate metabolism in plants that escaped Hassid's touch, and much that we know about the role of sugar nucleotides in the interconversion of carbohydrates in plants is a direct result of his persistent effort. From the incorporation of labeled precursors into monosaccharides, to the conversion of the monosaccharides to their glycosyl 1-phosphates, to the action of the pyrophosphorylases in the synthesis of the nucleoside diphosphate sugars, to the interconversion of the resulting sugar nucleotides, to the polymerization of the activated monosaccharides yielding disaccharides and the homopolysaccharides, and finally to the modification of the polysaccharides by methylation in summary, to almost every aspect of carbohydrate metabolism Hassid contributed his full and devoted attention.
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From page 213... ...
He was elected Chairman of the Division of Carbohydrate Chemistry ~ 1949-1950) , American Chemical Society, and he served as a member of numerous editorial boards, including those of the Journal of Biological Chemistry, Annual Review of Biochemistry, Carbohydrate Research, Phytochemtstry, and A nalytical Biochemistry.
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From page 214... ...
Rivka Ashbel (prepared for the celebration of Petah-Tikva's seventieth anniversary and based on conversations between Hassid and Ashbel in 1949~. Additionally, we had available a number of documents including Hassid's passport application, naturalization papers, and records of his service in the British army and service medals.
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From page 215... ...
Soc., 55:4163-67. 1935 The structure of sodium sulfuric acid ester of galactan from Irideae laminarioides (Rhodophyceae)
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The molecular constitution of enzymatically synthesized starch.
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Enzymatically synthesized crystalline sucrose.
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Dore. Isolation and structure of an enzymatically synthesized crystalline disaccharide, D-glucosido-D-ketoxyloside.
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The structure of an enzymatically synthesized reducing disaccharide, D-glucosidoL-arabinose.
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From page 220... ...
IV. The molecular constitution of amylose subfractions.
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Bean. Assimilation of C14O2 by a photosynthesizing red alga, Iridophycus flaccidum.
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Uridine diphosphate N-acetylglucosamine and uridine diphosphate glucuronic acid in mung bean seedlings.
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Synthesis of a ,8-1,3-linked glucan by extracts of Phaseolus aureus seedlings.
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Metabolism of D-glucuronic acid by Phaseolus aureus seedlings.
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Kessler. Phosphorylation of D-galacturonic acid by extracts from germinating seeds of Phaseolus aureus.
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Lin. Isolation of guanosine diphosphate D-mannuronic acid from the marine brown alga, Fucus gardneri Silva.
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Lin. Biosynthesis of the polygalacturonic acid chain of pectin by a particulate enzyme preparation from Phaseolus aureus seedlings.
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Franz. Biosynthesis of alkali insoluble polysaccharide from UDP-D-glucose with particulate enzyme preparations from Phaseolus aureus.
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Kemp. Biosynthesis of cellulose in vitro from guanosine diphosphate D-glucose with enzymic preparations from Phaseolus aureus and Lupinus albus.
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Chan. One step purification of D-galactose and Larabinose kineses from Phaseolus aureus seedlings by ATPsepharose affinity chromatograph.
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