In vitro enzymatic response of Turkish native chicken “Gerze” to heavy metal exposure

摘要

Abstract Glucose-6-phosphate dehydrogenase (G6PD) was purified and characterized from the Turkish native chicken, Gerze, erythrocytes for the first time, and some characteristics were investigated. Purification procedure consisted of ammonium sulphate fractionation and affinity chromatography on 29, 59-ADP Sepharose-4B. The enzyme was purified 1063.22-fold with a yield of 43.27% and specific activity of 93.5 EU/mg proteins. Kinetic parameters of the enzyme were determined with glucose-6-phosphate (G6P) as substrate and purified enzyme had an apparent K_M and V_max values of 0.222?mM and 0.097?U/ml, respectively. The same parameters were determined with NADP+ and the K_M and V_max values were 0.0603?mM and 0.153?U/ml, respectively. The following metals, Cd+2, Pb+2, Hg+2, Cu+2, Zn+2 and Fe+3 showed inhibitory effects on the enzyme. Cd+2 and Pb+2 exhibited the strongest inhibitory action. Hg+2 and Cu+2 were moderate inhibitors, whereas Zn+2 and Fe+3 showed weaker actions. All tested metals inhibited the enzyme in competitive manner.