منابع مشابه
Enzymic Catalysis
The time of greatest sensitivity to radiation is during the period of organogenesis in the first twelve weeks of human foetal development. Irradiation of the adult can cause life shortening or increased incidence of leukemia. The last chapter is concerned with the basis and origin of radiation protection standards, the hazards of nuclear power plants, high altitude supersonic aerospace travel, ...
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Group transfer reactions catalyzed by enzymes have assumed a position of intense interest in contemporary enzymology (1). Well known examples of radicals capable of being transferred in such reactions are methyl, glycosyl, aeetyl, phosphoryl, pept,idyl, nucleosidyl, and nucleotidyl, in addition to the transport of hydrogen as seen with the familiar nuoleot.ide coenzymes. In this paper we wish t...
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The principles that underlie enzyme catalysis also apply to energy coupling processes. A comparison is made between a kinase system that mediates the phosphorylation of glucose by ATP (hexokinase), as the prototype for enzymic catalysis, and the mitochondrial electron-transfer complexes, as the prototypes for energy coupling systems. Induced polarization of chemical bonds and charge separation ...
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This paper is a brief review of the detailed mechanism of action of thiamine enzymes, based on metal complexes of bivalent transition and post-transition metals of model compounds, thiamine derivatives, synthesized and characterized with spectroscopic techniques and X-ray crystal structure determinations. It is proposed that the enzymatic reaction is initiated with a V conformation of thiamine ...
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The present paper describes a new enzyme from animal tissues which catalyzes the keto-enol tautomeriaation of the phenylpyruvic acids. Preliminary accounts of this tautomerase have been published (1, 2). The enzyme has not yet proved to be essential in any biological reaction, but a physiological role may be expected since specific tautomers of a-keto acids are substrates or products in some re...
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ژورنال
عنوان ژورنال: Nature
سال: 1978
ISSN: 0028-0836,1476-4687
DOI: 10.1038/276542b0