Metabolism of cholesterol, vitamin D3 and 20-hydroxyvitamin D3 incorporated into phospholipid vesicles by human CYP27A1.

ABSTRACT: CYP27A1 is a mitochondrial cytochrome P450 which can hydroxylate vitamin D3 and cholesterol at carbons 25 and 26, respectively. The product of vitamin D3 metabolism, 25-hydroxyvitamin D3, is the precursor to the biologically active hormone, 1α,25-dihydroxyvitamin D3. CYP27A1 is attached to the inner mitochondrial membrane and substrates appear to reach the active site through the membrane phase. We have therefore examined the ability of bacterially expressed and purified CYP27A1 to metabolize substrates incorporated into phospholipid vesicles which resemble the inner mitochondrial membrane. We also examined the ability of CYP27A1 to metabolize 20-hydroxyvitamin D3 (20(OH)D3), a novel non-calcemic form of vitamin D derived from CYP11A1 action on vitamin D3 which has anti-proliferative activ

SUBMITTER: Tieu EW 

PROVIDER: S-EPMC3303980 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature