Akademik Veri Yönetim Sistemi
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, cilt.1070, ss.104-111, 2017 (SCI-Expanded)
Climate change and increasing temperatures are global concerns. Camel (Camelus dromedarius) lives most of its life under high environmental stress in the desert and represent ideal model for studying desert adaptation among mammals. Catalase plays a key role in protecting cells against oxidative stress. For the first time, catalase from camel liver was purified to homogeneity by zinc chelate affinity chromatography using pH gradient elution, a better separation was obtained. A purification fold of 201.81 with 1.17% yield and a high specific activity of 1132539.37 U/mg were obtained. The native enzyme had a molecular weight of 268 kDa and was composed of four subunits of equal size (65 kDa). The enzyme showed optimal activity at a temperature of 45 degrees C and pH 7.2. Thiol reagents, beta-Mercaptoethanol and D,L-Dithiothreitol, inhibited the enzyme activity. The enzyme was inhibited by Al3+, Cd2+ and Mg2+, whereas Ca2+, Co2+ and Ni2+ stimulated the catalase activity. Reduced glutathione has no effect on catalase activity. The K-m and V-max of the enzyme for hydrogen peroxide were 37.31 mM and 6185157 U/mg, respectively. Sodium azide inhibited the enzyme noncompetitively with K-1 value of 14.43 mu M, the IC50 was found to be 16.71 mu M. The properties of camel catalase were different comparing to those of mammalian species. Relatively higher molecular weight, higher optimum temperature, protection of reduced glutathione from hydrogen peroxide oxidation and higher affinity for hydrogen peroxide and sodium azide, these could be explained by the fact that camel is able to live in the intense environmental stress in the desert.