Pereira B, Sivakami S
Department of Life Sciences, University of Bombay, India.
Biochem J. 1991 Mar 1;274 ( Pt 2)(Pt 2):349-54. doi: 10.1042/bj2740349.
The neutral maltase-glucoamylase complex has been purified to homogeneity from the brush-border membrane of rabbit intestine and kidney. Chemical modification of the amino acid side chains was carried out on the purified enzymes. Studies on the kidney enzyme revealed that tryptophan, histidine and cysteine were essential for both maltase and glucoamylase activities, whereas tryptophan, histidine and lysine were essential for the maltase and glucoamylase activities of the intestinal enzyme. Though there was no difference in the amino acids essential for the hydrolysis of maltose and starch by any one enzyme, starch hydrolysis seems to require two histidine residues instead of the one which is required for maltose hydrolysis. This appears to be true for both the intestinal and kidney enzymes.
中性麦芽糖酶-葡糖淀粉酶复合物已从兔小肠和肾脏的刷状缘膜中纯化至同质。对纯化后的酶进行了氨基酸侧链的化学修饰。对肾脏酶的研究表明，色氨酸、组氨酸和半胱氨酸对麦芽糖酶和葡糖淀粉酶的活性均至关重要，而色氨酸、组氨酸和赖氨酸对肠道酶的麦芽糖酶和葡糖淀粉酶活性至关重要。尽管任何一种酶水解麦芽糖和淀粉所需的必需氨基酸没有差异，但淀粉水解似乎需要两个组氨酸残基，而不是麦芽糖水解所需的一个组氨酸残基。这似乎对肠道酶和肾脏酶都适用。
