Evidence for a covalent intermediate between α-glucosidase and glucose
Evidence for a covalent intermediate between α-glucosidase and glucose
复制标题
α-葡萄糖苷酶和葡萄糖之间存在共价中间体的证据
DOI：
10.1016/0006-291x(74)90288-5
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发表时间：
1974
影响因子：
3.1
通讯作者：
B. Axelrod
中科院分区：
文献类型：
--
作者：
H. L. Lai;L. Butler;B. Axelrod
在α-甲基-β-葡萄糖苷酶与α-甲基-14 C-吡喃葡萄糖苷的短时反应中，得到了一种稳定的酶-葡萄糖中间体。采用快速流动技术，其中苯酚用于终止反应并捕获产物。认为涉及共价键，因为（a）变性蛋白质的持续洗涤未能去除放射性和（B）放射性被通过凝胶过滤分离的胰蛋白酶肽保留。在室温下用2 N HCl处理标记蛋白，释放超过80%的放射性，作为具有与葡萄糖相同色谱迁移率的化合物。当牛血清白蛋白取代酶时，也没有形成放射性产物，当葡糖胺，一种有效的葡萄糖苷酶抑制剂，与酶一起存在时。
A stable enzyme-glucose intermediate has been obtained in the short-term reaction between α-methyl--glucosidase and α-methyl--14 C-glucopyranoside. A rapid-flow technique was employed in which phenol was used to terminate the reaction and to trap the product. It is believed that a covalent linkage is involved because (a) continued washing of the denatured protein failed to remove the radioactivity and (b) the radioactivity was retained by a tryptic peptide isolated by gel filtration. Treatment of the labeled protein with 2 N HCl at room temperature released over 80% of the radioactivity as a compound with the same chromatographic mobility as glucose. No radioactive product was formed when bovine serum albumin replaced the enzyme, nor when glucosylamine, a potent glucosidase inhibitor, was present with the enzyme.