[Some properties of two forms of alpha-glucosidase from Saccharomyces cerevisiae-II].
The amino acid composition of two forms of alpha-glucosidase from the yeast Saccharomyces cerevisiae-II was established and the values of Km, V, kcat and kcat/Km for maltose, maltotriose and p-nitrophenyl-alpha-D-glucopyranoside (PNPG) were determined. PNPG possessed a much higher affinity for the enzyme as compared to sucrose, maltose and maltotriose. The value of V decreased in the following order: PNPG greater than sucrose greater than maltose greater than greater than maltotriose. No differences between the kinetic parameters of individual forms of alpha-glucosidase were observed. Glucose, fructose and methyl-alpha-glucoside act as competitive inhibitors. The two forms of alpha-glucosidase under study have an identical pH optimum and thermal stability.
D000596:Amino Acids / Q000032:analysis; D005959:Glucosidases / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D007700:Kinetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity; D000520:alpha-Glucosidases / Q000378:metabolism*
D000596:Amino Acids; D007527:Isoenzymes; D005959:Glucosidases; D000520:alpha-Glucosidases
Nekotorye svoĭstva dvukh form al'fa-gliukozidazy Saccharomyces cerevisiae-II.