CHARACTERIZATION AND LOCALIZATION OF PROGESTERONE 5-ALPHA-REDUCTASE FROM CELL-CULTURES OF FOXGLOVE (DIGITALIS-LANATA EHRH)

被引:14
作者
WENDROTH, S
SEITZ, HU
机构
关键词
D O I
10.1042/bj2660041
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
Progesterone 5α-reductase, which catalyses the reduction of progesterone to 5α-pregnane-3,20-dione, was isolated and characterized from cell cultures of Digitalis lanata (foxglove). Optimum enzyme activity was observed at pH 7.0, and the enzyme had an apparent K(m) value of 30 μM for its substrate progesterone. THe enzyme needs NADPH as reductant, which could not be replaced by NADH. For NADPH, the apparent K(m) value is 130 μM. The optimum temperature was 40°C; at temperatures below 45°C, the product 5α-pregnane-3,20-dione was reduced by a second reaction to 5α-pregnan-3β-ol-20-one. Progesterone 5α-reductase activity was not dependent on bivalent cations. In the presence of EDTA, 0.1 mM-Mn2+ had no influence on enzyme activity, whereas 0.1 mM-Ca2+, -Co2+ and -Zn2+ decreased progesterone 5α-reductase activity. Only 0.1 mM-Mg2+ was slightly stimulatory. EDTA and thiol reagents such as dithiothreitol stimulate progesterone 5α-reductase activity. By means of linear sucrose gradient fractionation of the cellular membranes, progesterone 5α-reductase was found to be located in the endoplasmic reticulum
引用
收藏
页码:41 / 46
页数:6
相关论文
共 34 条
[1]   DETERGENT-SOLUBILIZATION, PURIFICATION, AND CHARACTERIZATION OF MEMBRANE-BOUND 3-HYDROXY-3-METHYLGLUTARYL-COENZYME-A REDUCTASE FROM RADISH SEEDLINGS [J].
BACH, TJ ;
ROGERS, DH ;
RUDNEY, H .
EUROPEAN JOURNAL OF BIOCHEMISTRY, 1986, 154 (01) :103-111
[2]   PROGESTERONE METABOLISM IN DIGITALIS LANATA [J].
BENNETT, RD ;
SAUER, HH ;
HEFTMANN, E .
PHYTOCHEMISTRY, 1968, 7 (01) :41-&
[3]   PARTIAL CHARACTERIZATION OF THE MICROSOMAL AND SOLUBILIZED HYPOTHALAMIC PROGESTERONE 5-ALPHA-REDUCTASE [J].
BERTICS, PJ ;
KARAVOLAS, HJ .
JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY, 1984, 21 (03) :305-314
[4]  
BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248, DOI 10.1016/0003-2697(76)90527-3
[5]  
CHENG YJ, 1975, J BIOL CHEM, V250, P7997
[6]  
DRAGER B, 1988, AGR BIOL CHEM TOKYO, V52, P2663
[7]  
FREDERIKSEN DW, 1971, J BIOL CHEM, V246, P2584
[8]   STUDIES ON PLANT TISSUE CULTURES .3. BIOTRANSFORMATION OF PROGESTERONE AND PREGNENOLONE BY PLANT SUSPENSION CULTURES [J].
FURUYA, T ;
HIROTANI, M ;
KAWAGUCHI, K .
PHYTOCHEMISTRY, 1971, 10 (05) :1013-+
[9]   STUDIES ON PLANT-TISSUE CULTURES .19. BIOTRANSFORMATION OF PROGESTERONE BY SUSPENSION CULTURES OF DIGITALIS-PURPUREA CULTURED CELLS [J].
FURUYA, T ;
KAWAGUCH.K ;
HIROTANI, M .
PHYTOCHEMISTRY, 1973, 12 (07) :1621-1626
[10]   RECONSTITUTION OF NADPH - 4-ENE-3-OXOSTEROID-5-ALPHA-OXIDOREDUCTASE FROM SOLUBILIZED COMPONENTS OF RAT-LIVER MICROSOMES [J].
GOLF, SW ;
GRAEF, V .
JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY, 1978, 9 (11) :1087-1092