Bico P, Erhardt J, Kaplan W, Dirr H
Department of Biochemistry, University of the Witwatersrand, Johannesburg, South Africa.
Biochim Biophys Acta. 1995 Mar 15;1247(2):225-30. doi: 10.1016/0167-4838(94)00236-a.
The equilibrium binding of the non-substrate ligands 8-anilino-1-naphthalene sulfonate and bromosulfophthalein to porcine class pi glutathione S-transferase (pGSTP1-1) was studied using a variety of techniques (size-exclusion HPLC, steady-state fluorescence, second-derivative spectroscopy, and chemical modification of cysteines). Both ligands share the same binding site which has a highly hydrophobic surface. Occupation of the site inhibits catalytic function with glutathione and 1-chloro-2,4-dinitrobenzene in a non-competitive manner. Data obtained from different structural probes either located at strategic regions of pGSTP1-1 (Trp-28, Trp-38 and Cys-45) or distributed throughout the protein molecule (tyrosine residues) suggest that binding induces a microstructural change that impacts on the functional conformation of the active site.
利用多种技术（尺寸排阻高效液相色谱法、稳态荧光法、二阶导数光谱法以及半胱氨酸的化学修饰）研究了非底物配体8-苯胺基-1-萘磺酸盐和溴磺酞与猪π类谷胱甘肽S-转移酶（pGSTP1-1）的平衡结合。这两种配体共享一个具有高度疏水表面的结合位点。该位点的占据以非竞争性方式抑制谷胱甘肽和1-氯-2,4-二硝基苯的催化功能。从位于pGSTP1-1的关键区域（色氨酸-28、色氨酸-38和半胱氨酸-45）或分布在整个蛋白质分子中的不同结构探针（酪氨酸残基）获得的数据表明，结合会诱导微观结构变化，从而影响活性位点的功能构象。
