Purification of glucose 6-phosphate dehydrogenase from gilthead sea bream (Sparus aurata) gill and liver tissues and inhibition effects of some metal ions on enzyme activity

Abstract

Fish is one of the most valuable protein sources and vulnerable to all environmental pollution including metals. Metals play vital roles in enzyme activities and other metabolic events with their bioaccumulative and nonbiodegradable properties among aquatic pollutants. Metal toxicity causes irregular metallothioneins protein synthesis, renal damage, and disruption of bone structure in humans and wildlife. In this study, we investigated in vitro effects of some metal ions on chemical-targeted glucose 6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) enzyme from gilthead sea bream (Sparus aurata) liver and gill tissues. In this purpose, G6PD was purified from gilthead sea bream liver and gill. The purification was performed by preparation of homogenates, ammonium sulphate precipitation and 2',5'-ADP Sepharose 4B affinity chromatography. Overall purification procedure, yield and purification fold for liver and gill were obtained as 54.6%, 52.2% and 1864.3, 283, respectively. The purify of the enzymes were checked by SDS-PAGE. Which shaved a single band. Additionally, inhibitory effects of some metal ions (Zn2+, Ni2+, Cd2+, Ag+, Cu2+ and Al3+) were examined the enzyme's activity in vitro by performing Lineweaver-Burk graphs and plotting activity% vs., respectively