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Cloning, expression, molecular modelling and docking analysis of glutathione transferase from Saccharum officinarum
Author(s) -
Ghelfi A.,
Gaziola S.A.,
Cia M.C.,
Chabregas S.M.,
Falco M.C.,
KuserFalcão P.R.,
Azevedo R.A.
Publication year - 2011
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.2011.00491.x
Subject(s) - glutathione , glutathione s transferase , biology , mutant , saccharum officinarum , biochemistry , enzyme , escherichia coli , docking (animal) , xenobiotic , gene , botany , medicine , nursing
Sugarcane yield and quality are affected by a number of biotic and abiotic stresses. In response to such stresses, plants may increase the activities of some enzymes such as glutathione transferase (GST), which are involved in the detoxification of xenobiotics. Thus, a sugarcane GST was modelled and molecular docked using the program LIGIN to investigate the contributions of the active site residues towards the binding of reduced glutathione (GSH) and 1‐chloro‐2,4‐dinitrobenzene (CDNB). As a result, W13 and I119 were identified as key residues for the specificity of sugarcane GSTF1 (SoGSTF1) towards CDNB. To obtain a better understanding of the catalytic specificity of sugarcane GST (SoGSTF1), two mutants were designed, W13L and I119F. Tertiary structure models and the same docking procedure were performed to explain the interactions between sugarcane GSTs with GSH and CDNB. An electron‐sharing network for GSH interaction was also proposed. The SoGSTF1 and the mutated gene constructions were cloned and expressed in Escherichia coli and the expressed protein purified. Kinetic analyses revealed different K m values not only for CDNB, but also for GSH. The K m values were 0.2, 1.3 and 0.3 mM for GSH, and 0.9, 1.2 and 0.5 mM for CDNB, for the wild type, W13L mutant and I119F mutant, respectively. The V max values were 297.6, 224.5 and 171.8 µmol min −1 mg −1 protein for GSH, and 372.3, 170.6 and 160.4 µmol min −1 mg −1 protein for CDNB.