Substrate and steric specificity of hydropyrimidine hydrase

Mutations of penicillin acylase residue B71 extend substrate specificity by decreasing steric constraints for substrate binding.

Two mutant forms of penicillin acylase from Escherichia coli strains, selected using directed evolution for the ability to use glutaryl-L-leucine for growth [Forney, Wong and Ferber (1989) Appl. Environ. Microbiol. 55, 2550-2555], are changed within one codon, replacing the B-chain residue Phe(B71) with either Cys or Leu. Increases of up to a factor of ten in k (cat)/ K (m) values for substrate...

Substrate Specificity of MMPs

The substrate specificity of fumarase.

The substrate specificity of fumarase has been studied by measuring the ability of the enzyme to hydrate or dehydrate derivatives of fumarate and L-malate. Fumarase was observed to hydrate fumarate and its derivatives in the order, fluorofumarate > fumarate > chlorofumarate > bromofumarate > acetylenedicarboxylate > iodofumarate > mesaconate. With the exception of fluorofumarate, water was adde...

2 Substrate Specificity of MMPs

Liver microsomal epoxide hydrase.

1. The substrate specificity of membrane-bound and purified epoxide hydrase from rat liver microsomes has been studied. Both enzyme preparations catalyzed the hydration of a variety of alkene oxidase as well as arene oxides of several polycyclic aromatic hydrocarbons. 2. Unlike the membrane-bound enzyme, the rate of hydration for most of the substrates catalyzed by the purified epoxide hydrase ...