UNIQUE PROPERTY OF LIVER MITOCHONDRIAL-P450 TO CATALYZE THE 2 PHYSIOLOGICALLY IMPORTANT REACTIONS INVOLVED IN BOTH CHOLESTEROL CATABOLISM AND VITAMIN-D ACTIVATION

The cDNA for vitamin D 25-hydroxylase in rat liver mitochondria was transfected in COS cells in order to confirm our previous postulation that both 5β-cholestane-3α,7α,12α-triol 27-hydroxylation and vitamin D 25-hydroxylation are catalyzed by a common enzyme. As a result it was found that both enzyme activities could be reconstituted from the solubilized extract of mitochondria of these cells. NADPH. NADPH-adrenodoxin reductase and adrenodoxin, giving unequivocal evidence that the two enzyme activities are catalyzed by a common enzyme. © 1990.