Studies on the Microbiological Degradation of Cholesterol

Stadtman, Thressa C.; Cherkes, Amelia; Anfinsen, Christian B.

doi:10.1016/s0021-9258(19)50819-5

Cited by 102 publications

(4 citation statements)

References 16 publications

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“…A wide range of soil bacteria share the ability to survive when grown on a medium of cholesterol, the degradation of which provides their sole source of carbon and energy (Stadtman et al, 1954;Fukuda etal., 1973). The first enzyme utilized in this degradation pathway is cholesterol oxidase (3/3-hydroxysteroid oxidase, EC 1.…”

mentioning

confidence: 99%

Crystal structure of cholesterol oxidase complexed with a steroid substrate: Implications for flavin adenine dinucleotide dependent alcohol oxidases

Li¹,

Vrielink²,

Brick³

et al. 1993

Biochemistry

185

216

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Cholesterol oxidase from Brevibacterium sterolicum is a flavin-dependent enzyme that catalyzes the oxidation and isomerization of 3 beta-hydroxy steroids with a double bond at delta 5-delta 6 of the steroid ring backbone. The crystal structure of the free enzyme in the absence of a steroid substrate has previously been determined. In this paper we report the crystal structure of the complex of cholesterol oxidase with the steroid substrate dehydroisoandrosterone, refined at 1.8-A resolution. The final crystallographic R-value is 15.7% for all reflections between 10.0- and 1.8-A resolution. The steroid is buried within the protein in an internal cavity which, in the free enzyme crystal structure, was occupied by a lattice of water molecules. The conformations of a number of side chains lining the active-site cavity have changed in order to accommodate the steroid substrate. A loop region of the structure between residues 70 and 90 differs significantly between the substrate-free and substrate-bound forms of the enzyme, presumably to facilitate binding of the steroid. The hydroxyl group of the steroid substrate is hydrogen-bonded to both the flavin ring system of the FAD cofactor and a bound water molecule. FAD-dependent cholesterol oxidase shares significant structural homology with another flavoenzyme, glucose oxidase, suggesting that it might also be a member of the glucose-methanol-choline (GMC) oxidoreductase family. Although there is only limited sequence homology, a superposition of these two structures reveals a conserved histidine residue within hydrogen-bonding distance of the active-site water molecule.(ABSTRACT TRUNCATED AT 250 WORDS)

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mentioning

confidence: 99%

Crystal structure of cholesterol oxidase complexed with a steroid substrate: Implications for flavin adenine dinucleotide dependent alcohol oxidases

Li¹,

Vrielink²,

Brick³

et al. 1993

Biochemistry

185

216

View full text Add to dashboard Cite

show abstract

“…the re-arrangement of the position of a double-bond from a Z -3- to an E -2-aldehyde, the main function of the enzyme might involve the simple catalysis of an oxidation-reduction reaction, often described for GMC oxidoreductases 42 , in which a CH-OH group acts as a hydrogen or electron donor. Such bi-functional GMC oxidoreductase activity has also been described for the cholesterol oxidase, which catalyzes both oxidation and isomerization of cholesterol to 4-cholesten-3-one 43 – 45 .…”

Section: Discussionmentioning

confidence: 82%

A salivary GMC oxidoreductase of Manduca sexta re-arranges the green leaf volatile profile of its host plant

et al. 2023

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Green leaf volatiles (GLVs) are short-chain oxylipins that are emitted from plants in response to stress. Previous studies have shown that oral secretions (OS) of the tobacco hornworm Manduca sexta, introduced into plant wounds during feeding, catalyze the re-arrangement of GLVs from Z-3- to E-2-isomers. This change in the volatile signal however is bittersweet for the insect as it can be used by their natural enemies, as a prey location cue. Here we show that (3Z):(2E)-hexenal isomerase (Hi-1) in M. sexta’s OS catalyzes the conversion of the GLV Z-3-hexenal to E-2-hexenal. Hi-1 mutants that were raised on a GLV-free diet showed developmental disorders, indicating that Hi-1 also metabolizes other substrates important for the insect’s development. Phylogenetic analysis placed Hi-1 within the GMCβ-subfamily and showed that Hi-1 homologs from other lepidopterans could catalyze similar reactions. Our results indicate that Hi-1 not only modulates the plant’s GLV-bouquet but also functions in insect development.

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“…Such bi-functional GMC oxidoreductase activity has also been described for the cholesterol oxidase, which catalyzes both oxidation and isomerization of cholesterol to 4-cholesten-3-one (Wongnate and Chaiyen 2013;Yamashita et al 1998;Stadtman et al 1954).…”

Section: Discussionmentioning

confidence: 85%

A salivary GMC oxidoreductase of Manduca sexta re-arranges the green leaf volatile profile of its host plant

Lin

Silven

Wybouw

et al. 2022

Preprint

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Green leaf volatiles (GLVs) are short-chain oxylipins that are emitted from plants in response to stress. Previous studies have shown that oral secretions (OS) of the tobacco hornworm Manduca sexta, introduced into plant wounds during feeding, catalyze the re-arrangement of GLVs from Z-3- to E-2-isomers. This change in the volatile signal however is bittersweet for the insect as it can be used by their natural enemies, as prey location cue. Here we identified a (3Z):(2E)-hexenal isomerase (Hi-1) in M. sexta’s OS that catalyzes the conversion of the GLV Z-3-hexenal to E-2-hexenal. Hi-1 mutants that were raised on a GLV-free diet showed developmental disorders, indicating that Hi-1 also metabolizes other substrates important for the insect’s development. Phylogenetic analysis placed Hi-1 within the GMCβ-subfamily and showed that Hi-1 homologs from other lepidopterans could catalyze similar reactions. Our results indicate that Hi-1 not only modulates the plant’s GLV-bouquet but also functions in insect development.

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Studies on the Microbiological Degradation of Cholesterol

Cited by 102 publications

References 16 publications

Crystal structure of cholesterol oxidase complexed with a steroid substrate: Implications for flavin adenine dinucleotide dependent alcohol oxidases

Crystal structure of cholesterol oxidase complexed with a steroid substrate: Implications for flavin adenine dinucleotide dependent alcohol oxidases

A salivary GMC oxidoreductase of Manduca sexta re-arranges the green leaf volatile profile of its host plant

A salivary GMC oxidoreductase of Manduca sexta re-arranges the green leaf volatile profile of its host plant

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