鸽子肠道双糖酶的研究。II. 亚细胞定位与增溶作用。

Studies on the intestinal disaccharidases of the pigeon. II. Subcellular localization and solubilization.

作者信息

Prakash K, Patil S D, Hegde S N

出版信息

Arch Int Physiol Biochim. 1982 Nov;90(4):255-64. doi: 10.3109/13813458209103822.

DOI:10.3109/13813458209103822

Abstract

In the pigeon, 70-80% of the activities of maltase (alpha-D-glucoside glucohydrolase EC 3.2.1.20), sucrase (alpha-glucohydrolase, EC 3.2.1.48), isomaltase (dextran 6-alpha-D-glucan hydrolase, EC 3.2.1.10) and glucoamylase (1,4-alpha-D-glucan glucohydrolase, EC 3.2.1.3) were found to be localized in the brush-border membrane of intestinal epithelial cells. Of the total glycosidase activities in the mucosal homogenate, nearly 60 to 70% were recovered in the microsomal (105 000 X g) fraction, about 30% in the mitochondrial (22 000 X g) fraction and less than 5% from the cytosol (105 000 X g supernatant) fraction. The hydrolases were solubilized by digestion with papain but not with trypsin, and the phosphate ion had a protective effect in the solubilization. Amongst detergents, Triton X-100 but not sodium deoxycholate, was found to truly solubilize these enzymes.

摘要

在鸽子中，发现麦芽糖酶（α-D-葡萄糖苷葡糖水解酶，EC 3.2.1.20）、蔗糖酶（α-葡糖水解酶，EC 3.2.1.48）、异麦芽糖酶（葡聚糖 6-α-D-葡聚糖水解酶，EC 3.2.1.10）和葡糖淀粉酶（1,4-α-D-葡聚糖葡糖水解酶，EC 3.2.1.3）70-80%的活性定位于肠上皮细胞的刷状缘膜中。在粘膜匀浆中的总糖苷酶活性中，近60%至70%在微粒体（105 000×g）组分中回收，约30%在线粒体（22 000×g）组分中回收，而在胞质溶胶（105 000×g上清液）组分中回收的不到5%。这些水解酶可通过木瓜蛋白酶消化而溶解，但不能被胰蛋白酶溶解，并且磷酸根离子在溶解过程中具有保护作用。在去污剂中，发现Triton X-100能真正溶解这些酶，而脱氧胆酸钠则不能。