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-C oA synthase genes have been described: HMGS-1 (Martinez-Gonzalez et al ,, 1993b) and HMGS-2 (Buesa ed al., 1994), The HMGS-1 gene showed spec ial features, which led us to characterize the kinetic properties of t he enzyme it encodes, Here we report the expression of recombinant HMG S-1, the protocol of enzyme purification, and the measurement of kinet ic 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 synth ases reported to date, (C) 1997 Elsevier Science Ltd.