Nad-dependent 3α- and 12α-hydroxysteroid dehydrogenase activities from eubacterwm lentum atcc no. 25559
作者:Ian A. MacDonald、David E. Mahony、Joanne F. Jellet、C.Elizabeth Meier
DOI:10.1016/0005-2760(77)90167-9
日期:1977.12
Eubacterium lentum (ATCC No. 25559) was shown to contain 3alpha-and 12alpha-hydroxysteroid dehydrogenases both of which were NAD-dependent and active against conjugated and unconjugated bile salts. In addition, the 3alpha-hydroxysteroid dehydrogenase was active against members of the Androstan series containing a 3alpha-hydroxyl group regardless of the stereo-orientation of the 5-H-. No measurable
Bile Salt Degradation by Nonfermentative Clostridia
作者:David E. Mahony、C. Elizabeth Meier、Ian A. Macdonald、Lillian V. Holdeman
DOI:10.1128/aem.34.4.419-423.1977
日期:1977.10
species (Clostridium group P) were studied. Both cultures of C. sporosphaeroides contained low amounts of 7alpha-HSDH; C. irregularis contained only a low amount of 3alpha-HSDH. All four strains of Clostridium SPH-1 contained both 12alpha- and 7alpha-HSDH in the ratio of approximately 10:1. The strain of Clostridium group P contained only 12alpha-HSDH and was devoid of any other bilesalt oxidoreductases
Characterization of NADP-dependent 12β-hydroxysteroid dehydrogenase from Clostridium paraputrificum
作者:Rudolf Edenharder、Andreas Pfützner
DOI:10.1016/0005-2760(88)90266-4
日期:1988.10
Clostridiumparaputrificum D 762-06 was found to contain an NADP-dependent 12 beta-hydroxysteroid dehydrogenase, already present in uninduced cells. Its specific activity could, however, be enhanced up to about 3-fold by the inclusion of bile acids with a 12-keto group or a 12 beta-hydroxy group in the growth medium. 3 alpha-Hydroxy-12-keto-5 beta-cholanoic acid was the most effective inducer. A pH
In search of sustainable chemical processes: cloning, recombinant expression, and functional characterization of the 7α- and 7β-hydroxysteroid dehydrogenases from Clostridium absonum
作者:Erica Elisa Ferrandi、Giulia Maria Bertolesi、Fausto Polentini、Armando Negri、Sergio Riva、Daniela Monti
DOI:10.1007/s00253-011-3798-x
日期:2012.9
dinucleotide phosphate-dependent 7α-hydroxysteroid dehydrogenase (7α-HSDH) and 7β-hydroxysteroiddehydrogenases (7β-HSDH) from Clostridiumabsonum catalyze the epimerization of primary bile acids through 7-keto bile acid intermediates and may be suitable as biocatalysts for the synthesis of bile acids derivatives of pharmacological interest. C. absonum 7α-HSDH has been purified to homogeneity and the
烟酸梭状芽孢杆菌的烟酰胺腺嘌呤二核苷酸磷酸依赖性7α-羟基类固醇脱氢酶(7α-HSDH)和7β-羟基类固醇脱氢酶(7β-HSDH)催化伯胆汁酸通过7-酮胆汁酸中间体发生差向异构化反应,可能适合用作生物催化具有药理学意义的胆汁酸衍生物的合成。枯草衣原体7α-HSDH已纯化至同质,N端序列已通过Edman测序确定。用简并引物对基因片段进行PCR扩增后,已通过对Absum C. absonum基因组DNA进行测序,克隆了完整的基因(786 nt)。通过对7α-HSDH基因5'末端侧翼的基因组DNA区域进行测序,获得了编码7β-HSDH(783 nt)的序列,这两个基因是连续的,可能是同一操纵子的一部分。插入合适的表达载体后,两种HSDHs已成功在大肠杆菌中以重组形式生产,通过亲和层析纯化,并进行了动力学分析,以确定米氏常数(K(m))和特异性常数(k(cat)/ K) (m))在各种胆汁酸衍生物