Marshall J J
Carbohydr Res. 1976 Jul;49:389-98. doi: 10.1016/s0008-6215(00)83156-0.
Bacillus amyloliquefaciens alpha-amylase was attached to dextran after activation of the polysaccharide by using a modification of the cyanogen bromide method. The soluble dextran-amylase conjugate was purified by molecular-sieve chromatography. The conjugated enzyme has greater stability than the unmodified enzyme at low pH values, during heat treatment, and on removal of calcium ions with a chelating agent. Attachment of dextran to alpha-amylase did not alter the Michaelis constant of the enzyme acting on starch. The polysaccharide-enzyme conjugate probably consists of a cross-linked aggregate of many dextran and many enzyme molecules, in which a proportion of the enzyme molecules, although not inactivated, are unable to express their activity, except after dextranase treatment.
解淀粉芽孢杆菌α-淀粉酶在使用溴化氰法的改良方法活化多糖后与葡聚糖相连。可溶性葡聚糖-淀粉酶结合物通过分子筛色谱法纯化。在低pH值、热处理过程中以及用螯合剂去除钙离子时，结合酶比未修饰的酶具有更高的稳定性。葡聚糖与α-淀粉酶的连接并未改变该酶作用于淀粉时的米氏常数。多糖-酶结合物可能由许多葡聚糖和许多酶分子的交联聚集体组成，其中一定比例的酶分子虽然没有失活，但除了经过葡聚糖酶处理外无法表达其活性。
