A STEREOSPECIFIC ENZYME OF THE PUTATIVE BIOSYNTHETIC-PATHWAY OF CARDENOLIDES - CHARACTERIZATION OF A PROGESTERONE 5-BETA-REDUCTASE FROM LEAVES OF DIGITALIS-PURPUREA L

被引：47

作者：

GARTNER, DE ^{[1
]}

WENDROTH, S ^{[1
]}

SEITZ, HU ^{[1
]}

机构：

[1] UNIV TUBINGEN,INST ALLGEMEINE BOT & PFLANZENPHYSIOL,MORGENSTELLE 1,W-7400 TUBINGEN 1,GERMANY

来源：

FEBS LETTERS | 1990年 / 271卷 / 1-2期

关键词：

Cardenolide; Digitalis purpurea; Progesterone; 5β-reductase;

D O I：

10.1016/0014-5793(90)80415-F

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：

Leaves of Digitalis purpurea contain an enzyme activity which catalyzes the conversion of progesterone to 5β-pregnane-3,20-dione. Since cardenolides without exception possess a 5β-configuration, 5β-pregnane-3,20-dione can serve as a precursor for this class of secondary metabolites. It is assumed that the enzyme is part of the putative biosynthetic pathway of cardenolides. This enzyme activity was spotted in the soluble fraction of a crude homogenate. Product formation was detected by gas chromatography and by gas chromatography/mass spectroscopy (g.c./m.s.). The enzyme had a pH optimum at 8.0 and an apparent Km value of 6 μM for progesterone. It required NADPH as a co-substrate with an apparent Km value of 22 μM. The optimum temperature in vitro was 30°C. The activity was not dependent on monovalent and bivalent cations. © 1990.

引用

页码：239 / 242

页数：4

共 8 条

[1] PROGESTERONE METABOLISM IN DIGITALIS LANATA [J].

BENNETT, RD ;

SAUER, HH ;

HEFTMANN, E .

PHYTOCHEMISTRY, 1968, 7 (01) :41-&

[2]

BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248, DOI 10.1016/0003-2697(76)90527-3

[3] THE MULTIPLICITY AND SPECIFICITY OF DELTA-4-3-KETOSTEROID HYDROGENASES (5-ALPHA) [J].

MCGUIRE, JS ;

TOMKINS, GM .

ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1959, 82 (02) :476-477

[4] DELTA-5-3-BETA-HYDROXYSTEROID DEHYDROGENASE DELTA-5-DELTA-4-KETOSTEROID ISOMERASE (3-BETA-HSD), A POSSIBLE ENZYME OF CARDIAC GLYCOSIDE BIOSYNTHESIS, IN CELL-CULTURES AND PLANTS OF DIGITALIS-LANATA EHRH [J].

SEIDEL, S ;

KREIS, W ;

REINHARD, E .

PLANT CELL REPORTS, 1990, 8 (10) :621-624

[5] BIOGENESIS OF CARDENOLIDS IN DIGITALIS-LANATA [J].

TSCHESCH.R ;

HOMBACH, R ;

SCHOLTEN, H ;

PETERS, M .

PHYTOCHEMISTRY, 1970, 9 (07) :1505-&

[6] DISTRIBUTION OF CARDENOLIDES IN DIGITALIS-LANATA [J].

VOGEL, E ;

LUCKNER, M .

PLANTA MEDICA, 1981, 41 (02) :161-165

[7]

WARNECK HM, 1990, IN PRESS Z NATURFORS

[8] CHARACTERIZATION AND LOCALIZATION OF PROGESTERONE 5-ALPHA-REDUCTASE FROM CELL-CULTURES OF FOXGLOVE (DIGITALIS-LANATA EHRH) [J].

WENDROTH, S ;

SEITZ, HU .

BIOCHEMICAL JOURNAL, 1990, 266 (01) :41-46

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