The chapter describes procedures for the purification of the pregnancy-inducible rabbit lung cytochrome P-450 prostaglandin ω-hydroxylase. Pulmonary microsomes from pregnant rabbits or female rabbits pretreated with progesterone or human chorionic gonadotropin catalyze the co-hydroxylation of prostaglandins and related eicosanoids, an activity that is very low or absent in nonpregnant or control rabbits. A unique cytochrome P-450 does not catalyze the ω- or (ω-1)-hydroxylation of lauric acid or the N-demethylation of benzphetamine activities, which are associated with distinct rabbit lung cytochromes P-450.A similar, if not identical, cytochrome P-450 [P-450p-2 or P-450IVA4 has been purified from pulmonary microsomes of female rabbits pretreated with progesterone and has been shown to catalyze the ω-hydroxylation of medium- and long-chain fatty acids and prostaglandins. The procedure involves the initial isolation of total rabbit lung microsomal cytochrome P-450 by aminooctyl-Sepharose chromatography followed by separation of the rabbit lung cytochromes P-450 by chromatography on DEAE-Sepharose. Removal of detergent from the enzymes is then performed by chromatography on hydroxylapatite or by hydrophobic absorption chromatography.
ASJC Scopus subject areas
- Molecular Biology