A functionally conserved basic residue in glutathione transferases interacts with the glycine moiety of glutathione and is pivotal for enzyme catalysis.

ABSTRACT: The present study characterized conserved residues in a GST (glutathione transferase) in the active-site region that interacts with glutathione. This region of the active site is near the glycine moiety of glutathione and consists of a hydrogen bond network. In the GSTD (Delta class GST) studied, adGSTD4-4, the network consisted of His(38), Met(39), Asn(47), Gln(49), His(50) and Cys(51). In addition to contributing to glutathione binding, this region also had major effects on enzyme catalysis, as shown by changes in kinetic parameters and substrate-specific activity. The results also suggest that the electron distribution of this network plays a role in stabilization of the ionized thiol of glutathione as well as impacting on the catalytic rate-limiting step. This area constitutes a second

SUBMITTER: Vararattanavech A 

PROVIDER: S-EPMC1948969 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature