Purification and Characterization of 3-Oxoacyl-CoA Synthase of Mycobacterium smegmatis

摘要: 3-Oxoacyl-CoA synthase, that condenses malonyl-CoA to other acyl-CoAs and takes part in the malonyl-CoA-dependent, acyl carrier protein (ACP)-non-requiring fatty acid elongation system ("fatty II or II" (Kikuchi, S. & Kusaka, T. (1982) J. Biochem. 92, 839-844)), was purified homogeneity for first time from crude extract of Mycobacterium smegmatis by column-chromatographies. The molecular weight this enzyme estimated be around 64,000 Sephacryl S-300 gel filtration 59,000 sodium dodecyl sulfate-polyacrylamide electrophoresis. enzymic product stearoyl-CoA identified as 3-oxoeicosanoyl-CoA mass-spectrometry. Km values were 41.7 microM 52.6 microM, respectively. more active toward having acyl-carbon-numbers 18 more, either saturated monounsaturated, than those with below 18. Cerulenin, a specific inhibitor 3-oxoacyl-ACP synthase [EC 2.3.1.41], had no effect on but iodoacetamide N-ethylmaleimide (NEM) showed inhibitory effects.