Transfected human liver cytochrome P-450 hydroxylates vitamin D analogs at different side-chain positions - PubMed (original) (raw)

Transfected human liver cytochrome P-450 hydroxylates vitamin D analogs at different side-chain positions

Y D Guo et al. Proc Natl Acad Sci U S A. 1993.

Abstract

A full-length cDNA for the human liver mitochondrial cytochrome P-450 CYP27 was cloned from a human hepatoma HepG2 cDNA library and then subcloned into the mammalian expression vector pSG5. When CYP27 cDNA was transfected into COS-1 transformed monkey kidney cells along with adrenodoxin cDNA, transfected cells revealed a 10- to 20-fold higher vitamin D3-25-hydroxylase activity than nontransfected cells. Transfected cells were capable of 25-hydroxylation of vitamin D3, 1 alpha-hydroxyvitamin D3 and 1 alpha-hydroxydihydrotachysterol3. In each case they also showed the ability to 26(27)-hydroxylate the cholesterol-like (D3) side chain. The relative rates of 25- and 26(27)-hydroxylation of 1 alpha-hydroxyvitamin D3 approximately mimicked the ratio of products observed in HepG2 cells. Vitamin D2 and 1 alpha-hydroxyvitamin D2, both with the ergosterol-like side chain, were 24- and 26(27)-hydroxylated by CYP27. The rate of side-chain 24-, 25-, or 26(27)-hydroxylation was greater for 1 alpha-hydroxylated vitamin D analogs than for their nonhydroxylated counterparts. We conclude that CYP27 is capable of 24-, 25-, and 26(27)-hydroxylation of vitamin D analogs and that the nature of products is partially dictated by the side chain of the substrate. This work has revealed that the cytochrome P-450 CYP27 may be important in the metabolism of vitamin D analogs used as drugs.

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References

    1. DNA Cell Biol. 1991 Jan-Feb;10(1):1-14 - PubMed
    1. J Biol Chem. 1991 Apr 25;266(12):7774-8 - PubMed
    1. J Biol Chem. 1991 Apr 25;266(12):7779-83 - PubMed
    1. J Biol Chem. 1993 Jan 5;268(1):282-92 - PubMed
    1. FEBS Lett. 1976 Jun 1;65(2):211-4 - PubMed

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