The C-terminus of glutathione S-transferase A1-1 is required for entropically-driven ligand binding.

ABSTRACT: Binding of a hydrophobic glutathione product conjugate to rGST A1-1 proceeds via a two-step mechanism, including rapid ligand docking, followed by a slow isomerization to the final [GST.ligand] complex, which involves the localization of the flexible C-terminal helix. These kinetically resolved steps have been observed previously by stopped-flow fluorescence with the wild-type rGST A1-1, which contains a native Trp-21 approximately 20 A from the ligand binding site at the intrasubunit domain-domain interface. To confirm this binding mechanism, as well as elucidate the effects of truncation of the C-terminus, we have further characterized the binding and dissociation of the glutathione-ethacrynic acid product conjugate (GS-EA) to wild-type, F222W:W21F, and Delta209-222 rGST A1-1 and wild-ty

SUBMITTER: Nieslanik BS 

PROVIDER: S-EPMC1866267 | biostudies-literature | 2001 Mar

REPOSITORIES: biostudies-literature