Microbial degradation of the phytosterol side chain. I. Enzymic conversion of 3-oxo-24-ethylcholest-4-en-26-oic acid into 3-oxochol-4-en-24-oic acid and androst-4-ene-3,17-dione

Fujimoto, Yoshinori; Chen, Ching Shih; Szeleczky, Z.; Ditullio, Dennis; Sih, Charles J.

doi:10.1021/ja00381a055

Cited by 41 publications

(16 citation statements)

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“…Furthermore, due to the structure of C24-branched chain sterols, formation of a ketoacyl-CoA at the b-carbon, essential for thiolase activity, is chemically impossible. Fujimoto et al (1982a) suggested that sterol C24-branches are cleaved off by an aldol-lyase reaction, similar to that of other tertiary b-hydroxy-CoA esters, such as (b-methyl-)malyl-CoA (Hacking & Quayle, 1974) and hydroxymethylglutaryl-CoA (Stegink & Coon, 1968).…”

Section: Discussionmentioning

confidence: 99%

Molecular characterization of ltp3 and ltp4, essential for C24-branched chain sterol-side-chain degradation in Rhodococcus rhodochrous DSM 43269

2012

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A previously identified sterol catabolic gene cluster is widely dispersed among actinobacteria, enabling them to degrade and grow on naturally occurring sterols. We investigated the physiological roles of various genes by targeted inactivation in mutant RG32 of Rhodococcus rhodochrous, which selectively degrades sterol side-chains. The ltp3 and ltp4 deletion mutants were each completely blocked in side-chain degradation of b-sitosterol and campesterol, but not of cholesterol. These results indicated a role for ltp3 and ltp4 in the removal of C24 branches specifically. Bioinformatic analysis of the encoded Ltp3 and Ltp4 proteins revealed relatively high similarity to thiolase enzymes, typically involved in b-oxidation, but the catalytic residues characteristic for thiolase enzymes are not conserved in their amino acid sequences. Removal of the C24-branched side-chain carbons of b-sitosterol was previously shown to proceed via aldolytic cleavage rather than by b-oxidation. Our results therefore suggest that ltp3 and ltp4 probably encode aldol-lyases rather than thiolases. This is the first report, to our knowledge, on the molecular characterization of genes with specific and essential roles in carbon-carbon bond cleavage of C24-branched chain sterols in Rhodococcus strains, most likely acting as aldollyases. The results are a clear contribution to our understanding of sterol degradation in actinobacteria.

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Section: Discussionmentioning

confidence: 99%

Molecular characterization of ltp3 and ltp4, essential for C24-branched chain sterol-side-chain degradation in Rhodococcus rhodochrous DSM 43269

2012

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“…In earlier studies, degradation of the steroid side chain was shown with cell extracts of different Mycobacterium strains leading from 3-oxo-24-ethylcholest-4-en-26-oic acid and lithocholic acid to the respective 17-keto products (35,36). However, there were no CoA esters or other intermediates detected in those earlier studies.…”

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confidence: 96%

Degradation of the Acyl Side Chain of the Steroid Compound Cholate in Pseudomonas sp. Strain Chol1 Proceeds via an Aldehyde Intermediate

Holert¹,

Kulić²,

Yücel³

et al. 2012

Journal of Bacteriology

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Bacterial degradation of steroids is widespread, but the metabolic pathways have rarely been explored. Previous studies with Pseudomonas sp. strain Chol1 and the C 24 steroid cholate have shown that cholate degradation proceeds via oxidation of the A ring, followed by cleavage of the C 5 acyl side chain attached to C-17, with 7␣,12␤-dihydroxy-androsta-1,4-diene-3,17-dione (12␤-DHADD) as the product. In this study, the pathway for degradation of the acyl side chain of cholate was investigated in vitro with cell extracts of strain Chol1. For this, intermediates of cholate degradation were produced with mutants of strain Chol1 and submitted to enzymatic assays containing coenzyme A (CoA), ATP, and NAD ؉ as cosubstrates. When the C 24 steroid (22E)-7␣,12␣-dihydroxy-3-oxochola-1,4,22-triene-24-oate (DHOCTO) was used as the substrate, it was completely transformed to 12␣-DHADD and 7␣-hydroxy-androsta-1,4-diene-3,12,17-trione (HADT) as end products, indicating complete removal of the acyl side chain. The same products were formed with the C 22 steroid 7␣,12␣-dihydroxy-3-oxopregna-1,4-diene-20-carboxylate (DHOPDC) as the substrate. The 12-keto compound HADT was transformed into 12␤-DHADD in an NADPH-dependent reaction. When NAD ؉ was omitted from assays with DHOCTO, a new product, identified as 7␣,12␣-dihydroxy-3-oxopregna-1,4-diene-20S-carbaldehyde (DHOPDCA), was formed. This aldehyde was transformed to DHOPDC and DHOPDC-CoA in the presence of NAD ؉ , CoA, and ATP. These results revealed that degradation of the C 5 acyl side chain of cholate does not proceed via classical ␤-oxidation but via a free aldehyde that is oxidized to the corresponding acid. The reaction leading to the aldehyde is presumably catalyzed by an aldolase encoded by the gene skt, which was previously predicted to be a ␤-ketothiolase.

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“…Đó là nhờ phát minh một số chủng vi sinh phân cắt chọn lọc mạch nhánh của chúng đến 17-ketosteroid như androstendion (AD), androstadiendion (ADD), 9αhydroxyandrostendion (9α-OH AD). [1,2] Đã có nhiều công trình công bố tổng hợp cocticoid từ AD, 9α-OH AD. [3][4][5] Một trong số các giai đoạn quan trọng nhất tổng hợp cocticoid từ 17-ketosteroid là xây dựng mạch bên pregnan và tạo lập liên kết đôi-1 (2).…”

Section: Mở đầUunclassified

Con đường mới tổng hợp 21‐acetoxypregn‐1,4,9(11)‐trien‐17α,21‐diol‐3,20‐dion

Diệp¹,

Huy²

2018

Vietnam Journal of Chemistry

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In this paper, we present an convernient procedure for synthesis of 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione from 9α-hydroxyandrostenedione, an key intermediate for synthesis of corticoids such as prednisolone, dexamethasone, betamethasone, etc. The strusture of the product and its intermediates was examined by physical methods such as: IR, MS, 1 H and 13 C-NMR Keywords. 9α-hydroxyandrostenedione, 21-acetoxypregna-1,4,9(11)-triene-17α,21-diol-3,20-dione.

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Microbial degradation of the phytosterol side chain. I. Enzymic conversion of 3-oxo-24-ethylcholest-4-en-26-oic acid into 3-oxochol-4-en-24-oic acid and androst-4-ene-3,17-dione

Cited by 41 publications

References 0 publications

Molecular characterization of ltp3 and ltp4, essential for C24-branched chain sterol-side-chain degradation in Rhodococcus rhodochrous DSM 43269

Molecular characterization of ltp3 and ltp4, essential for C24-branched chain sterol-side-chain degradation in Rhodococcus rhodochrous DSM 43269

Degradation of the Acyl Side Chain of the Steroid Compound Cholate in Pseudomonas sp. Strain Chol1 Proceeds via an Aldehyde Intermediate

Con đường mới tổng hợp 21‐acetoxypregn‐1,4,9(11)‐trien‐17α,21‐diol‐3,20‐dion

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