Malá S, Dvoráková H, Hrabal R, Králová B
Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague, Czech Republic.
Carbohydr Res. 1999 Dec 12;322(3-4):209-18. doi: 10.1016/s0008-6215(99)00222-0.
alpha-Glucosidase from two microbial sources, Bacillus stearothermophilus and Brewer's yeast, has been used to catalyze transglycosylation reactions and a comparative study was carried out to determine the regioselectivity of this reaction. Bacterial alpha-glucosidase exhibited higher transfer activity with maltose and was able to synthesize tri- and tetrasaccharides in high yield (27%). In the case of yeast enzyme, only trisaccharides were synthesized in lower yield. Structure analysis of transglycosylation products by means of GC-MS and NMR spectroscopy revealed a correlation between the hydrolytic substrate specificity and the regioselectivity of transglycosylation reaction. Higher substrate specificity of bacterial enzyme, however, influenced its transglucosylation activity toward other saccharide acceptors.
来自嗜热脂肪芽孢杆菌和酿酒酵母这两种微生物源的α-葡萄糖苷酶已被用于催化转糖基化反应，并进行了一项比较研究以确定该反应的区域选择性。细菌α-葡萄糖苷酶对麦芽糖表现出更高的转移活性，并且能够高产率（27%）地合成三糖和四糖。对于酵母酶，仅以较低产率合成了三糖。通过气相色谱-质谱联用（GC-MS）和核磁共振光谱（NMR）对转糖基化产物进行结构分析，揭示了水解底物特异性与转糖基化反应区域选择性之间的相关性。然而，细菌酶较高的底物特异性影响了其对其他糖类受体的转葡糖基化活性。
