6561-58-6Relevant academic research and scientific papers
Structural and biochemical characterization of Mycobacterium tuberculosis CYP142: Evidence for multiple cholesterol 27-hydroxylase activities in a human pathogen
Driscoll, Max D.,McLean, Kirsty J.,Levy, Colin,Mast, Natalia,Pikuleva, Irina A.,Lafite, Pierre,Rigby, Stephen E. J.,Leys, David,Munro, Andrew W.
experimental part, p. 38270 - 38282 (2011/10/13)
The Mycobacterium tuberculosis cytochrome P450 enzyme CYP142 is encoded in a large gene cluster involved in metabolism of host cholesterol. CYP142 was expressed and purified as a soluble, low spin P450 hemoprotein. CYP142 binds tightly to cholesterol and its oxidized derivative cholest-4-en-3-one, with extensive shift of the heme iron to the high spin state. High affinity for azole antibiotics was demonstrated, highlighting their therapeutic potential. CYP142 catalyzes either 27-hydroxylation of cholesterol/cholest-4-en-3-one or generates 5-cholestenoic acid/cholest-4-en-3-one-27-oic acid from these substrates by successive sterol oxidations, with the catalytic outcome dependent on the redox partner system used. The CYP142 crystal structure was solved to 1.6 A, revealing a similar active site organization to the cholesterol-metabolizing M. tuberculosis CYP125, but having a near-identical organization of distal pocket residues to the branched fatty acid oxidizing M. tuberculosis CYP124. The cholesterol oxidizing activity of CYP142 provides an explanation for previous findings that ΔCYP125 strains of Mycobacterium bovis and M. bovis BCG cannot grow on cholesterol, because these strains have a defective CYP142 gene. CYP142 is revealed as a cholesterol 27-oxidase with likely roles in host response modulation and cholesterol metabolism.
Synthesis of potential C27-intermediates in bile acid biosynthesis and their deuterium-labeled analogs
Shoda, Junichi,Axelson, Magnus,Sjoevall, Jan
, p. 119 - 125 (2007/10/02)
In connection with studies of alternative pathways in bile acid biosynthesis, potential intermediates in a pathway starting with 27-hydroxylation of cholesterol have been prepared in natural and deuterated forms. Established methods were used to prepare 27-hydroxycholesterol and 3β-hydroxy-5-cholestenoic acid. Clemmensen reduction of kryptogenin in unlabeled and deuterated solvents yielded 27-hydroxycholesterol and 16-oxo-5-cholestene-3β,27-diol, which were separated by adsorption chromatography on Unisil. The labeled 27-hydroxycholesterol and 3β-hydroxy-5-cholestenoic acid derived from it consisted of molecules with seven (50%), six (20%), and eight (20%) deuterium atoms, and unlabeled molecules were not detected. The acetates of 27-hydroxycholesterol and methyl 3β-hydroxy-5-cholestenoate were 7α-hydroxylated in a copper-catalyzed reaction with ert-butylperbenzoate, and the products were purified by chromatography on Unisil. The 7β-epimers were obtained as side products. Labeled 3β, 7α-dihydroxy-5-cholenic acid was prepared in the same way from 3β-hydroxy-5-[2,2,4,4,23-2H5]-cholenoic acid. The 3-oxo-Δ4 analogs of the 3β-hydroxy-Δ5 compounds were prepared by oxidation with cholesterol oxidase. The labeled products had the same isotopic composition as the starting materials. Gas chromatographic retention indices and mass spectral characteristics of the trimethylsilyl ether derivatives of the neutral steroids and the methylated acids are given for all compounds. (Steroids 58:119-125, 1993).
