PREFERENTIAL CYCLIZATION OF 2,3(S)/22(S),23-DIOXIDOSQUALENE BY MAMMALIAN 2,3-OXIDOSQUALENE-LANOSTEROL CYCLASE

被引:33
作者
BOUTAUD, O [1 ]
DOLIS, D [1 ]
SCHUBER, F [1 ]
机构
[1] FAC PHARM ILLKIRCH,CHIM BIOORGAN LAB,CNRS,URA 1386,74 ROUTE RHIN,F-67400 ILLKIRCH GRAFFENS,FRANCE
关键词
D O I
10.1016/0006-291X(92)91140-L
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
Kinetic studies on the cyclization of 2,3(S)-oxido and 2,3(S):22(S),23-dioxido[14C]squa-lene catalyzed by liver oxidosqualene-lanosterol cyclase revealed a specificity (in terms of V /Km) of the enzyme for the diepoxide. The specificity ratio was dependent on the enzyme preparation, i.e. purified or microsomal, and was highest (about 5) with the microsomal enzyme m the presence of supernatant protein factors. These results explain why, in the presence of cyclase inhibitors, the squalene epoxides can be channeled into a cholesterol biosynthesis regulatory pathway via 24(S),25-epoxylanosterol and 24(S),25-epoxycholesterol. © 1992.
引用
收藏
页码:898 / 904
页数:7
相关论文
共 19 条
[11]  
NELSON JA, 1981, J BIOL CHEM, V256, P1067
[12]  
Orsi B A, 1979, Methods Enzymol, V63, P159
[13]  
PANINI SR, 1986, J LIPID RES, V27, P1190
[14]  
PANINI SR, 1984, J BIOL CHEM, V259, P7767
[15]   EFFECTS OF 3BETA-[2-(DIETHYLAMINO)ETHOXY]ANDROST-5-EN-17-ONE ON THE SYNTHESIS OF CHOLESTEROL AND UBIQUINONE IN RAT INTESTINAL EPITHELIAL-CELL CULTURES [J].
SEXTON, RC ;
PANINI, SR ;
AZRAN, F ;
RUDNEY, H .
BIOCHEMISTRY, 1983, 22 (25) :5687-5692
[16]   STEROID BIOSYNTHESIS - RELATIVE EFFICIENCIES OF ENZYMIC TRANSFORMATION OF TERMINALLY MODIFIED SQUALENE 2,3-OXIDE ANALOGS INTO LANOSTEROL ANALOGS BY 2,3-OXIDOSQUALENE CYCLASE [J].
SHISHIBORI, T ;
FUKUI, T ;
SUGA, T .
CHEMISTRY LETTERS, 1973, (12) :1289-1292
[17]  
TAYLOR FR, 1986, J BIOL CHEM, V261, P5039
[18]  
WILLETT JD, 1967, J BIOL CHEM, V242, P4182
[19]  
XIAO MX, 1992, BIOCHEM BIOPH RES CO, V185, P323