The stereochemical course of the reaction mechanism of trehalose phosphorylase from Schizophyllum commune.
Phosphorolysis of alpha,alpha-trehalose catalyzed by trehalose phosphorylase from the basidiomycete Schizophyllum commune proceeds via net retention of anomeric configuration and yields alpha-D-glucose 1-phosphate and alpha-D-glucose as the products. In reverse reaction, only the alpha-anomers of D-glucose 1-phosphate and D-glucose are utilized as glucosyl donor and acceptor, respectively, and give exclusively the alpha,alpha-product. Trehalose phosphorylase converts alpha-D-glucose 1-fluoride and phosphate into alpha-D-glucose 1-phosphate, a reaction requiring the stereospecific protonation of the glucosyl fluoride by a Brønsted acid. The results are discussed with regard to a plausible reaction mechanism of fungal trehalose phosphorylase.
Eis
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Division of Biochemical Engineering, Institute of Food Technology, Universität für Bodenkultur (BOKU), Wien, Austria.
Albert
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Dax
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Nidetzky
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B
D005947:Glucose / Q000031:analogs & derivatives / Q000378:metabolism; D005964:Glucosyltransferases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D012567:Schizophyllum / Q000201:enzymology* / Q000378:metabolism; D013237:Stereoisomerism; D013379:Substrate Specificity; D013997:Time Factors
C030364:glucosyl fluoride; D005964:Glucosyltransferases; C023181:alpha,alpha-trehalose phosphorylase; D005947:Glucose