title: New food for an old mouth: new enzyme for an ancient archaea.
abstract: As a multifunctional group of enzymes, glutathione S-transferases (GSTs) are capable of inactivation, degradation or excretion of wide range of compounds catalytically or non-catalytically. However, to date, no study has been addresses the presence of GSTs in archaea based on their enzymatic functions. In this study, beside glutathione (GSH) amount measurement, the determination of GST activity in halophilic archaeon called Haloarcula hispanica ATCC 33960 were aimed. According to the results, specific activity was determined as 19.68 nmol min⁻¹ mg⁻¹ protein and GSH content were found to be as 194 μg g⁻¹ K(m) and V(max) values for CDNB and GSH calculated from Lineweaver-Burk plot were 0.46 mM and 27.93 nmol min⁻¹ mg⁻¹, 0.13 mM and 22.03 nmol min⁻¹ mg⁻¹, respectively. Hanes-Woolf and Eadie-Hofstee plots for CDNB and GSH were also found to be in co-relation with the results obtained from Lineweaver-Burk plot. To the best of our knowledge, GST enzymes have not been identified in archaea yet, at least based on their catalytic activities. Therefore, it is the first report on this area.
authors.affiliation: Anadolu University, Science Faculty, Department of Biology, Eskisehir, Turkey. Electronic address: eoztetik@anadolu.edu.tr.
authors.forename: Elif
authors.initials: E
authors.lastname: Oztetik
authors.affiliation: Anadolu University, Science Faculty, Department of Biology, Eskisehir, Turkey.
authors.forename: Ayse
authors.initials: A
authors.lastname: Cakir
mesh_terms: D019843:Archaeal Proteins / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D003979:Diazonium Compounds / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D019613:Haloarcula / Q000201:enzymology* / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D054712:Salinity; D013696:Temperature
chemical_list: C504881:4-carboxyl-2,6-dinitrobenzenediazonium ion; D019843:Archaeal Proteins; D003979:Diazonium Compounds; D005979:Glutathione Peroxidase; D005978:Glutathione
keywords: Archaea; Glutathione; Glutathione S-transferase; Haloarcula hispanica; Optimization