title: Insights into ligand binding to a glutathione S-transferase from mango: Structure, thermodynamics and kinetics.
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, Vmaxand kcatfor CDNB of 0.792 mM, 80.58 mM min-1and 68.49 s-1respectively and 0.693 mM, 105.32 mM min-1and 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.
authors.affiliation: Laboratorio de Estructura Biomolecular, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico; Laboratorio de Genética Molecular de Plantas, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Valenzuela-Chavira
authors.affiliation: Laboratorio de Genética Molecular de Plantas, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico. Electronic address: contreras@ciad.mx.
authors.forename: Carmen A
authors.initials: CA
authors.lastname: Contreras-Vergara
authors.affiliation: Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, Sonora 83000, Mexico.
authors.forename: Aldo A
authors.initials: AA
authors.lastname: Arvizu-Flores
authors.affiliation: CONACyT, Laboratorio de Bioingeniería, Universidad de Colima, Coquimatlán, Colima 28629, Mexico.
authors.forename: Hugo
authors.initials: H
authors.lastname: Serrano-Posada
authors.affiliation: Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, Sonora 83000, Mexico.
authors.forename: Alonso A
authors.initials: AA
authors.lastname: Lopez-Zavala
authors.affiliation: Laboratorio de Estructura Biomolecular, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico.
authors.forename: Karina D
authors.initials: KD
authors.lastname: García-Orozco
authors.affiliation: Departamento de Física, Universidad de Sonora, Hermosillo, Sonora 83000, Mexico.
authors.forename: Javier
authors.initials: J
authors.lastname: Hernandez-Paredes
authors.affiliation: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos 62210, Mexico.
authors.forename: Enrique
authors.initials: E
authors.lastname: Rudiño-Piñera
authors.affiliation: Brookhaven National Laboratory, Photon Science Directorate, Upton, NY 11973, USA.
authors.forename: Vivian
authors.initials: V
authors.lastname: Stojanoff
authors.affiliation: Laboratorio de Estructura Biomolecular, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico. Electronic address: rrs@ciad.mx.
authors.forename: Rogerio R
authors.initials: RR
authors.lastname: Sotelo-Mundo
authors.affiliation: Laboratorio de Genética Molecular de Plantas, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Islas-Osuna
mesh_terms: D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D031022:Mangifera / Q000201:enzymology*; D011485:Protein Binding
chemical_list: D005982:Glutathione Transferase; D005978:Glutathione
keywords: Crystal structure; Detoxification; Glutathione; Glutathione S-transferase; Isothermal titration calorimetry; Mangifera indica; Mango; S-hexyl glutathione; Tau class