Observations on the Mechanism of the Reversible Epimerization of GDP-D-mannose to GDP-L-galactose by an Enzyme from ChZoreZZu pyrenoidosa*
نویسنده
چکیده
An enzyme fraction from the green alga Chlorella pyrenoidosa that catalyzes the reversible epimerization of guanosine B’diphosphate D-mannose to guanosine 5’-diphosphate L-galactose brings about the incorporation of tritium from tritium-labeled water into the hexosyl moieties of those sugar nucleotides. The hexoses were degraded by periodate oxidation whereby the tritium was found to be equally distributed between carbon atoms 3 and 5. That observation was taken to imply that the epimerizations proceed via ene-diol intermediates.
منابع مشابه
A bifunctional epimerase-reductase acts downstream of the MUR1 gene product and completes the de novo synthesis of GDP-L-fucose in Arabidopsis.
L-Fucose is a monosaccharide found as a component of glycoproteins and cell wall polysaccharides in higher plants. The MUR1 gene of Arabidopsis thaliana encodes a GDP-D-mannose 4,6-dehydratase catalyzing the first step in the de novo synthesis of GDP-L-fucose from GDP-D-mannose (Bonin et al. 1997, Proc. Natl Acad. Sci. USA, 94, 2085-2090). Plant genes encoding the subsequent steps in L-fucose s...
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تاریخ انتشار 2002