The Enzymatic Hydroxylation of n-Octane by Corynebacterium sp. Strain 7E1C

Abstract

Abstract Cell-free extracts from sonically disrupted Corynebacterium sp. (7E1C) oxidized n-octane to 1-octanol and octanoic acid in the presence of NADH and O2. The hydroxylating activity, assayed by direct estimation of the reaction products, was found to be concentrated in the clarified S3 suprenatant fraction after centrifugation at 144,000 x g for 2 hours. By use of mass spectrometry it was shown that molecular oxygen is incorporated into the substrate during hydroxylation. The hydroxylating enzyme system was separated into two protein fractions, both of which were required for activity. One fraction, the S3(25–40)D, which precipitated between 25 and 40% ammonium sulfate saturation, appeared particulate and contained cytochrome P-450. The participation of this hemoprotein in n-octane hydroxylation was established by inhibition, induction, and spectral studies. The S3(60–100)D fraction, which precipitated between 60 and 100% ammonium sulfate saturation, was soluble, contained flavoprotein, and was functional in reducing cytochrome P-450 or cytochrome c in the presence of NADH. A tentative scheme for n-octane hydroxylation in the Corynebacterium 7E1C system is proposed.