title: Azole-antifungal binding to a novel cytochrome P450 from Mycobacterium tuberculosis: implications for treatment of tuberculosis.
abstract: Although antibiotics against Mycobacterium tuberculosis have decreased the incidence of tuberculosis infections significantly, the emergence of drug-resistant strains of this deadly pathogen renders current treatments ineffective. Therefore, it is imperative to identify biochemical pathways in M. tuberculosis that can serve as targets for new anti-mycobacterial drugs. We recently cloned, expressed, and purified MT CYP51, a soluble protein from M. tuberculosis that is similar in sequence to CYP51 (lanosterol-14alpha-demethylase) isozymes, pharmacological targets for several anti-mycotic compounds. Its striking amino acid sequence similarity to that of mammalian and fungal CYP51s led to the hypothesis that MT CYP51 plays an important role in mycobacterial biology that can be targeted for drug action. In this manuscript, we established through spectral analysis that several azole antifungals bind MT CYP51 with high affinity. The effects of several azole compounds on the growth of M. bovis and M. smegmatis, two mycobacterial species that closely resemble M. tuberculosis were examined. We established a correlation between the affinity of azole compounds to MT CYP51 and their ability to impair the growth of M. bovis and M. smegmatis. These results suggest that the metabolic functions of MT CYP51 may be comparable to those of CYP51 in yeast and fungi and may lead to the development of a new generation of anti-mycobacterial agents.
authors.affiliation: Department of Biology, Trinity College, 300 Summit St., Hartford, CT 06106, USA. hebe.guardioladiaz@mail.trincoll.edu
authors.forename: H M
authors.initials: HM
authors.lastname: Guardiola-Diaz
authors.forename: L A
authors.initials: LA
authors.lastname: Foster
authors.forename: D
authors.initials: D
authors.lastname: Mushrush
authors.forename: A D
authors.initials: AD
authors.lastname: Vaz
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000494:pharmacology; D000995:Antitubercular Agents / Q000494:pharmacology*; D001393:Azoles / Q000494:pharmacology*; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009163:Mycobacterium bovis / Q000166:cytology / Q000187:drug effects; D020102:Mycobacterium smegmatis / Q000166:cytology / Q000187:drug effects; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology; D010088:Oxidoreductases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D013057:Spectrum Analysis; D058886:Sterol 14-Demethylase
chemical_list: D000935:Antifungal Agents; D000995:Antitubercular Agents; D001393:Azoles; D011994:Recombinant Proteins; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D058886:Sterol 14-Demethylase