PROPERTIES OF A PARTICULATE SQUALENE EPOXIDASE FROM CANDIDA-ALBICANS

被引：36

作者：

RYDER, NS ^{[1
]}

DUPONT, MC ^{[1
]}

机构：

[1] SANDOZ FORSCHUNGSINST, BRUNNER STR 59, A-1235 VIENNA, AUSTRIA

来源：

BIOCHIMICA ET BIOPHYSICA ACTA | 1984年 / 794卷 / 03期

关键词：

D O I：

10.1016/0005-2760(84)90013-4

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The properties and requirements of squalene epoxidase and effects of some inhibitors were investigated in the pathogenic yeast C. albicans. A washed microsomal fraction converted radiolabeled squalene to 2,3-oxidosqualene and lanosterol. Minimum requirements for activity were O2, NADH or NADPH, and FAD. Epoxidase activity was stimulated by up to 100% by addition of the soluble cytoplasmic fraction, which itself contained negligible epoxidase activity. This stimulation was most powerful at low concentrations of enzyme, or high concentrations of squalene. Divalent cations did not stimulate activity and EDTA was not inhibitory. An apparent Km for squalene of 50 .mu.M was determined in the presence of soluble cytoplasm. Epoxidase activity was destroyed by Triton X-100, deoxycholate or Cu2+, and partially inhibited by thiol reagents, rotenone and antimycin A. The enzyme was not inhibited by cyanide or by several inhibitors of cytochrome P-450.

引用

页码：466 / 471

页数：6

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