Solubilization and partial characterization of alkylglycerol monooxygenase from rat liver microsomes

The enzyme alkylglycerol monooxygenase was solubilized with 2% of Triton X-100 and partially purified approximately to 83-fold with a 36% yield after a procedure which included 6-aminohexyl-Sepharose and DEAE-cellulose column chromatography, followed by a sucrose density gradient centrifugation. The molecular weight of the native form was estimated to be approximately 400000 as judged by Sepharose 6B column chromatography in the presence of Triton X-100. The enzyme had a pH optimum near 8.5 and a Km of 0.66 mM for 1-O-hexadecylglycerol. The microsomal alkylglycerol monooxygenase was stimulated by Triton X-100, but did not affect kinetically the initial velocity except to maintain it for a much longer period of time. The purified enzyme required absolutely both molecular oxygen and reduced pteridine as an electron donor. Furthermore, reduced glutathione and phospholipids were necessary for expression of full enzyme activity. N-Ethylmaleimide and p-chloromercuribenzoate significantly inhibited the enzyme activity, suggesting that alkylglycerol monooxygenase is a -SH enzyme.