Catalytic properties of recombinant 3-hydroxy-3-methylglutaryl coenzyme A synthase-1 from Blattella germanica

Blattella germanica is the first organism in which two cytosolic HMG-CoA synthase genes have been described: HMGS-1 (Martinez-Gonzalez et al,, 1993b) and HMGS-2 (Buesa ed al., 1994), The HMGS-1 gene showed special features, which led us to characterize the kinetic properties of the enzyme it encodes, Here we report the expression of recombinant HMGS-1, the protocol of enzyme purification, and the measurement of kinetic parameters, The K-m for acetyl-CoA is 15.2 mu M and the K-i for the other substrate, acetoacetyl-CoA, is 1.26 mu M, both similar to that of yeast, ox, and chicken liver enzymes; the V-max of HMGS-1 measured in this paper is 66 mU, which is the lowest V-max of the HMG-CoA synthases reported to date, (C) 1997 Elsevier Science Ltd.