Krakenaĭte R P, Glemzha A A
Biokhimiia. 1983 Jan;48(1):62-8.
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.
测定了酿酒酵母-II中两种形式的α-葡萄糖苷酶的氨基酸组成，并确定了其对麦芽糖、麦芽三糖和对硝基苯基-α-D-吡喃葡萄糖苷（PNPG）的米氏常数（Km）、最大反应速度（V）、催化常数（kcat）和催化效率（kcat/Km）。与蔗糖、麦芽糖和麦芽三糖相比，PNPG对该酶具有更高的亲和力。V值按以下顺序降低：PNPG＞蔗糖＞麦芽糖＞＞麦芽三糖。未观察到各形式α-葡萄糖苷酶动力学参数之间的差异。葡萄糖、果糖和甲基-α-葡萄糖苷起竞争性抑制剂的作用。所研究的两种形式的α-葡萄糖苷酶具有相同的最适pH和热稳定性。
