Molecular cloning and functional characterization of Oxidosqualene Cyclases from Hoodia gordonii

Hoodia gordonii (Asclepiadacecae) a native of Kalahari deserts of South Africa, Namibia, and Botswana is one of the most prevalent herbal supplements for weight loss. The appetite suppressant properties are attributed to P57AS3, an oxypregnane steroidal glycoside. At the molecular level, the enzymes involved in biosynthesis of triterpenes and steroidal glycosides in H. gordonii have not been reported in the literature. In an attempt to isolate genes encoding enzymes involved in this biosynthesis process, we identified and cloned two putative oxidosqualene cyclases, designated HgCS1 and HgCS2, from publicly-available RNA-seq data prepared from H. gordonii. Sequence analysis and initial observations suggest that the two cyclases belong to lupeol synthase and cycloartenol synthase.

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