Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19).
A recently isolated hitherto unknown Clostridium from human feces, designated Clostridium ''scindens'' (formerly strain 19), synthesizes at least two enzymes active on the side-chain of the steroid molecule and two enzymes active on the hydroxyl groups of the 7-position of bile a...
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1984-10-01
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doaj-7b7425e214794580a6a96e17eb693c092021-04-26T13:50:26ZengElsevierJournal of Lipid Research0022-22751984-10-01251011241131Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19).J WinterG N MorrisS O'Rourke-LocascioV D BokkenheuserE H MosbachB I CohenP B HylemonA recently isolated hitherto unknown Clostridium from human feces, designated Clostridium ''scindens'' (formerly strain 19), synthesizes at least two enzymes active on the side-chain of the steroid molecule and two enzymes active on the hydroxyl groups of the 7-position of bile acids. Steroid desmolase, responsible for side-chain cleavage of corticoids, and 20 alpha-hydroxysteroid dehydrogenase have not been detected in any other bacterial species of the resident colonic flora. Steroid desmolase is Eh-dependent (optimum ca. -130 mV), requires a hydroxy group at C-17, and preferably an alpha-ketol group in the side-chain; an alpha-hydroxy group at C-20 reduces and a beta-hydroxy group at C-20 prevents side-chain cleavage. With suitable substrates, the yield of C-19 steroids is proportional to the bacterial multiplication rate. 20 alpha-Hydroxysteroid dehydrogenase (20 alpha-HSDH) is also Eh-dependent (optimum ca. -300 mV) and reduces the C-20 keto function to an alpha-hydroxy group, regardless of the presence or absence of a hydroxy group at C-17. 7 alpha-Dehydroxylase metabolizes cholic and chenodeoxycholic acid, while 7 beta-hydroxysteroid dehydrogenase acts upon ursodeoxycholic acid. The latter two enzymes are not specific for C. scindens.http://www.sciencedirect.com/science/article/pii/S0022227520377221 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
J Winter G N Morris S O'Rourke-Locascio V D Bokkenheuser E H Mosbach B I Cohen P B Hylemon |
spellingShingle |
J Winter G N Morris S O'Rourke-Locascio V D Bokkenheuser E H Mosbach B I Cohen P B Hylemon Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19). Journal of Lipid Research |
author_facet |
J Winter G N Morris S O'Rourke-Locascio V D Bokkenheuser E H Mosbach B I Cohen P B Hylemon |
author_sort |
J Winter |
title |
Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19). |
title_short |
Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19). |
title_full |
Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19). |
title_fullStr |
Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19). |
title_full_unstemmed |
Mode of action of steroid desmolase and reductases synthesized by Clostridium 'scindens' (formerly Clostridium strain 19). |
title_sort |
mode of action of steroid desmolase and reductases synthesized by clostridium 'scindens' (formerly clostridium strain 19). |
publisher |
Elsevier |
series |
Journal of Lipid Research |
issn |
0022-2275 |
publishDate |
1984-10-01 |
description |
A recently isolated hitherto unknown Clostridium from human feces, designated Clostridium ''scindens'' (formerly strain 19), synthesizes at least two enzymes active on the side-chain of the steroid molecule and two enzymes active on the hydroxyl groups of the 7-position of bile acids. Steroid desmolase, responsible for side-chain cleavage of corticoids, and 20 alpha-hydroxysteroid dehydrogenase have not been detected in any other bacterial species of the resident colonic flora. Steroid desmolase is Eh-dependent (optimum ca. -130 mV), requires a hydroxy group at C-17, and preferably an alpha-ketol group in the side-chain; an alpha-hydroxy group at C-20 reduces and a beta-hydroxy group at C-20 prevents side-chain cleavage. With suitable substrates, the yield of C-19 steroids is proportional to the bacterial multiplication rate. 20 alpha-Hydroxysteroid dehydrogenase (20 alpha-HSDH) is also Eh-dependent (optimum ca. -300 mV) and reduces the C-20 keto function to an alpha-hydroxy group, regardless of the presence or absence of a hydroxy group at C-17. 7 alpha-Dehydroxylase metabolizes cholic and chenodeoxycholic acid, while 7 beta-hydroxysteroid dehydrogenase acts upon ursodeoxycholic acid. The latter two enzymes are not specific for C. scindens. |
url |
http://www.sciencedirect.com/science/article/pii/S0022227520377221 |
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