title: Biochemical Characterization of the Detoxifying Enzyme Glutathione Transferase P1-1 from the Camel Camelus Dromedarius.
abstract: Glutathione transferase (GST, EC 2.5.1.18) is a primary line of defense against toxicities of electrophile compounds and oxidative stress and therefore is involved in stress-response and cell detoxification. In the present study, we investigated the catalytic and structural properties of the glutathione transferase (GST) isoenzyme P1-1 from Camelus dromedarius (CdGSTP1-1). Recombinant CdGSTP1-1 was produced in Escherichia coli BL21(DE3) and purified to electrophoretic homogeneity. Kinetic analysis revealed that CdGSTP1-1 displays broad substrate specificity and shows high activity towards halogenated aryl-compounds, isothiocyanates and hydroperoxides. Computation analysis and structural comparison of the catalytic and ligand binding sites of CdGSTP1-1 with other pi class GSTs allowed the identification of major structural variations that affect the active site pocket and the catalytic mechanism., Affinity labeling and kinetic inhibition studies identified key regions that form the ligandin-binding site (L-site) and gave further insights into the mechanism of non-substrate ligand recognition. The results of the present study provide new information into camelid detoxifying mechanism and new knowledge into the diversity and complex enzymatic functions of GST superfamily.
authors.affiliation: Laboratory of Enzyme Technology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, 75 Iera Odos Street, Athens, GR-11855, Greece.
authors.forename: Fereniki
authors.initials: F
authors.lastname: Perperopoulou
authors.affiliation: Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.|Molecular Biology Department, Genetic Engineering Division, National Research Centre, 33 El-Bohouth St. (former El-Tahrir St.), P.O. 12622, Dokki, Giza, Egypt.
authors.forename: Farid S
authors.initials: FS
authors.lastname: Ataya
authors.affiliation: Department of Zoology, College of Science, King Saud University, P.O. Box 22452, Riyadh, 11459, Saudi Arabia.|Department of Zoology and Entomology, Faculty of Science, Helwan University, Ein Helwan, Cairo, Egypt.
authors.forename: Dalia
authors.initials: D
authors.lastname: Fouad
authors.affiliation: Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.|Protein Research Chair, Department of Biochemistry, College of Science, King Saud University, PO Box 2455, Riyadh, 11451, Saudi Arabia.
authors.forename: Ajamaluddin
authors.initials: A
authors.lastname: Malik
authors.affiliation: Department of Biotechnology, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt.
authors.forename: Hesham Mahmoud
authors.initials: HM
authors.lastname: Saeed
authors.affiliation: Laboratory of Enzyme Technology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, 75 Iera Odos Street, Athens, GR-11855, Greece. lambrou@aua.gr.
authors.forename: Nikolaos E
authors.initials: NE
authors.lastname: Labrou
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002162:Camelus / Q000378:metabolism*; D003001:Cloning, Molecular; D019295:Computational Biology; D004926:Escherichia coli / Q000378:metabolism; D051549:Glutathione S-Transferase pi / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D055550:Protein Stability; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature; D014783:Viscosity
chemical_list: D011994:Recombinant Proteins; D051549:Glutathione S-Transferase pi
keywords: Glutathione transferase; Kinetic analysis; One-humped camel; Xenobiotics