3HJO

Crystal Structure of Glutathione Transferase Pi Y108V Mutant in Complex with the Glutathione Conjugate of Ethacrynic Acid

Summary for 3HJO

• Entry DOI: 10.2210/pdb3hjo/pdb
• Related: 3HJM 3HKR
• Descriptor: Glutathione S-transferase P, GLUTATHIONE, ETHACRYNIC ACID, ... (6 entities in total)
• Functional Keywords: transferase, glutathione, detoxification, ethacrynic acid, ethacrynic acid-glutathione conjugate
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 47946.46

Authors

Parker, L.J. (deposition date: 2009-05-22, release date: 2009-09-22, Last modification date: 2023-11-01)

Primary citation

Quesada-Soriano, I.,Parker, L.J.,Primavera, A.,Casas-Solvas, J.M.,Vargas-Berenguel, A.,Baron, C.,Morton, C.J.,Mazzetti, A.P.,Lo Bello, M.,Parker, M.W.,Garcia-Fuentes, L.
Influence of the H-site residue 108 on human glutathione transferase P1-1 ligand binding: structure-thermodynamic relationships and thermal stability.
Protein Sci., 18:2454-2470, 2009

PubMed Abstract: The effect of the Y108V mutation of human glutathione S-transferase P1-1 (hGST P1-1) on the binding of the diuretic drug ethacrynic acid (EA) and its glutathione conjugate (EASG) was investigated by calorimetric, spectrofluorimetric, and crystallographic studies. The mutation Tyr 108 --> Val resulted in a 3D-structure very similar to the wild type (wt) enzyme, where both the hydrophobic ligand binding site (H-site) and glutathione binding site (G-site) are unchanged except for the mutation itself. However, due to a slight increase in the hydrophobicity of the H-site, as a consequence of the mutation, an increase in the entropy was observed. The Y108V mutation does not affect the affinity of EASG for the enzyme, which has a higher affinity (K(d) approximately 0.5 microM) when compared with those of the parent compounds, K(d) (EA) approximately 13 microM, K(d) (GSH) approximately 25 microM. The EA moiety of the conjugate binds in the H-site of Y108V mutant in a fashion completely different to those observed in the crystal structures of the EA or EASG wt complex structures. We further demonstrate that the Delta C(p) values of binding can also be correlated with the potential stacking interactions between ligand and residues located in the binding sites as predicted from crystal structures. Moreover, the mutation does not significantly affect the global stability of the enzyme. Our results demonstrate that calorimetric measurements maybe useful in determining the preference of binding (the binding mode) for a drug to a specific site of the enzyme, even in the absence of structural information.

PubMed: 19780048
DOI: 10.1002/pro.253

Experimental method

X-RAY DIFFRACTION (1.95 Å)