Influence of multiple cysteines on human 3-hydroxy-3-methylglutaryl-CoA lyase activity and formation of inter-subunit adducts.

ABSTRACT: Human 3-hydroxy-3-methylglutaryl-CoA lyase catalyzes formation of acetyl-CoA and acetoacetate in a reaction that requires divalent cation and is stimulated by sulfhydryl protective reagents. The enzyme is a homodimer and inter-subunit adducts form in the absence of reducing agents or upon treatment with cysteine selective crosslinking agents. To address the influence of cysteines on enzyme activity and formation of inter-subunit and intra-subunit adducts, single serine substitutions have been engineered for each enzyme cysteine. Enzyme activity varies for each cysteine→serine mutant protein and different mutations have widely different effects on recovery of activity upon DTT treatment of non-reduced enzyme. These levels of enzyme activity do not strongly correlate with formation of inter-

SUBMITTER: Montgomery C 

PROVIDER: S-EPMC3130621 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature