Nuccetelli M, Mazzetti A P, Rossjohn J, Parker M W, Board P, Caccuri A M, Federici G, Ricci G, Lo Bello M
Department of Biology, University of Rome "Tor Vergata," Via della Ricerca Scientifica, Rome, 00133, Italy.
Biochem Biophys Res Commun. 1998 Nov 9;252(1):184-9. doi: 10.1006/bbrc.1998.9575.
Substrate selectivity, among glutathione transferase (GST) isoenzymes, appears to be determined by a few residues. As part of study to determine which residues are class-specific determinants, Tyr 108 (an important residue of the class Pi) has been changed to a valine, the structural equivalent of a class Alpha enzyme. Using a panel of selected substrates, "diagnostic" for either class Pi or Alpha, it is shown here that this single mutation significantly alters the catalytic properties of the class Pi enzyme and shifts the substrate specificity of the enzyme toward that of the class Alpha enzyme.
谷胱甘肽转移酶（GST）同工酶之间的底物选择性似乎由少数几个残基决定。作为确定哪些残基是类别特异性决定因素研究的一部分，108位酪氨酸（Pi类的一个重要残基）已被替换为缬氨酸，缬氨酸是α类酶的结构等效物。使用一组对Pi类或α类具有“诊断性”的选定底物，本文表明，这一单点突变显著改变了Pi类酶的催化特性，并使该酶的底物特异性向α类酶的底物特异性转变。
