Retention of anomeric form in lysozyme-catalyzed reaction.
Retention of anomeric form in lysozyme-catalyzed reaction.
复制标题
在溶菌酶催化反应中保留异头形式。
DOI：
10.1016/0003-9861(87)90649-7
复制
发表时间：
1987
影响因子：
3.9
通讯作者：
S. Goto
中科院分区：
文献类型：
--
作者：
Y. Yanase;T. Fukamizo;K. Hayashi;S. Goto
溶菌酶催化的反应由β-1,4-氨基葡萄糖链的断裂开始，随后是水合作用和转糖基化。由于所有由转糖基化产生的糖苷在糖和受体部分之间都有β-糖苷键，因此溶菌酶催化的反应被归类为氨基保留反应。然而，对底物水解产生的新还原性残留物的异头保留尚无实验证据。在本研究中，试图确定新生水解产物中还原端GlcNAc残基的球端形态。采用高效液相色谱法对酶解产物的异构体进行分离和定量分析。测定了产物中α-和β-异头物的含量与反应时间的关系。实验数据的计算机分析表明，新生水解产物仅以β-异头物形式存在，α-异头物是由β-异头物通过旋变形成的。
A lysozyme-catalyzed reaction is initiated by a cleavage of the β-1,4-glucosaminide linkage, followed by hydration and transglycosylation. Since all glycosides produced by transglycosylation have β-glycosidic linkages between the sugar and the acceptor moieties, the lysozyme-catalyzed reaction has been classified as an anomer-retention reaction. However, there is no experimental evidence on the anomer retention of the new reducing residue produced by the hydrolysis of the substrate. In the present study, an attempt was made to determine the anomeric form of the GlcNAc residue at the reducing end in nascent hydrolytic products. The anomeric forms of the enzymatic products were separated and quantitatively analyzed by high-performance liquid chromatography. The amounts of α- and β-anomers in the product were plotted against the reaction time. Computer analysis of the experimental data indicated that the nascent hydrolytic product takes only the β-anomeric form and that the α-anomer is formed from β-anomer by mutarotation.