Substrate preferences and catalytic parameters determined by structural characteristics of sterol 14α-demethylase (CYP51) from Leishmania infantum

Tatiana Y. Hargrove, Zdzislaw Wawrzak, Jialin Liu, W. David Nes, Michael R. Waterman, Galina I. Lepesheva*

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    72 Scopus citations

    Abstract

    Leishmaniasis is a major health problem that affects populations of ∼90 countries worldwide, with no vaccine and only a few moderately effective drugs. Here we report the structure/ function characterization of sterol 14α-demethylase (CYP51) from Leishmania infantum. The enzyme catalyzes removal of the 14α-methyl group from sterol precursors. The reaction is essential for membrane biogenesis and therefore has great potential to become a target for antileishmanial chemotherapy. Although L. infantum CYP51 prefers C4-monomethylated sterol substrates such as C4-norlanosterol and obtusifoliol (V max of ∼10 and 8min -1, respectively), it is also found to 14α-demethylate C4-dimethylated lanosterol (V max=0.9 min -1) and C4-desmethylated 14α-methylzymosterol (V max=1.9 min -1). Binding parameters with six sterols were tested, with Kd values ranging from 0.25 to 1.4μM. Thus, L. infantum CYP51 is the first example of a plant-like sterol 14α-demethylase, where requirements toward the composition of the C4 atom substituents are not strict, indicative of possible branching in the postsqualene portion of sterol biosynthesis in the parasite. Comparative analysis of three CYP51 substrate binding cavities (Trypanosoma brucei, Trypanosoma cruzi, and L. infantum) suggests that substrate preferences of plant- and fungal-like protozoan CYP51s largely depend on the differences in the enzyme active site topology. These minor structural differences are also likely to underlie CYP51 catalytic rates and drug susceptibility and can be used to design potent and specific inhibitors.

    Original languageEnglish (US)
    Pages (from-to)26838-26848
    Number of pages11
    JournalJournal of Biological Chemistry
    Volume286
    Issue number30
    DOIs
    StatePublished - Jul 29 2011

    ASJC Scopus subject areas

    • Biochemistry
    • Molecular Biology
    • Cell Biology

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