| Literature DB >> 28104507 |
Ignacio Valenzuela-Chavira1, Carmen A Contreras-Vergara2, Aldo A Arvizu-Flores3, Hugo Serrano-Posada4, Alonso A Lopez-Zavala3, Karina D García-Orozco5, Javier Hernandez-Paredes6, Enrique Rudiño-Piñera7, Vivian Stojanoff8, Rogerio R Sotelo-Mundo9, Maria A Islas-Osuna10.
Abstract
We studied a mango glutathione S-transferase (GST) (Mangifera indica) bound to glutathione (GSH) and S-hexyl glutathione (GSX). This GST Tau class (MiGSTU) had a molecular mass of 25.5 kDa. MiGSTU Michaelis-Menten kinetic constants were determined for their substrates obtaining a Km, Vmax and kcat for CDNB of 0.792 mM, 80.58 mM min-1 and 68.49 s-1 respectively and 0.693 mM, 105.32 mM min-1 and 89.57 s-1, for reduced GSH respectively. MiGSTU had a micromolar affinity towards GSH (5.2 μM) or GSX (7.8 μM). The crystal structure of the MiGSTU in apo or bound to GSH or GSX generated a model that explains the thermodynamic signatures of binding and showed the importance of enthalpic-entropic compensation in ligand binding to Tau-class GST enzymes.Entities:
Keywords: Crystal structure; Detoxification; Glutathione; Glutathione S-transferase; Isothermal titration calorimetry; Mangifera indica; Mango; S-hexyl glutathione; Tau class
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Year: 2017 PMID： 28104507 PMCID： PMC5346462 DOI： 10.1016/j.biochi.2017.01.005
Source DB: PubMed Journal: Biochimie ISSN： 0300-9084 Impact factor: 4.079