Substrate analog studies of the ω-regiospecificity of Mycobacterium tuberculosis cholesterol metabolizing cytochrome P450 enzymes CYP124A1, CYP125A1 and CYP142A1.
We report the synthesis and evaluation of a series of cholesterol side-chain analogs as mechanistic probes of three important Mycobacterium tuberculosis cytochrome P450 enzymes that selectively oxidize the ω-position of the methyl-branched cholesterol side-chain. To probe the structural requirements for the thermodynamically disfavored ω-regiospecificity we compared the binding of these substrate analogs to each P450, determined the turnover rates, and characterized the enzymatic products. The results are discussed in the context of the structure-activity relationships of the enzymes and how their active sites enforce ω-oxidation.
Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco 94158-2517, USA.
Jonathan B
JB
Johnston
Arti A
AA
Singh
Anaelle A
AA
Clary
Chiung-Kuan
CK
Chen
Patricia Y
PY
Hayes
Sharon
S
Chow
James J
JJ
De Voss
Paul R
PR
Ortiz de Montellano
D055162:Biocatalysis; D020134:Catalytic Domain; D002784:Cholesterol / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D010084:Oxidation-Reduction; D011485:Protein Binding; D020033:Protein Isoforms / Q000378:metabolism; D013237:Stereoisomerism; D013379:Substrate Specificity
D020033:Protein Isoforms; D003577:Cytochrome P-450 Enzyme System; D002784:Cholesterol