Characterization of carbonic anhydrase from Turkish native "Gerze" chicken and influences of metal ions on enzyme activity

Abstract

Carbonic anhydrase was purified and characterized from erythrocytes of the Turkish native chicken, Gerze, for the first time. The enzyme was purified 57.65-fold with a yield of 52%, and a specific activity of 954.08 U/mg proteins having optimum pH at 8.0; optimum temperature at 30 degrees C; optimum ionic strength at 10 mM and stable pH at 8.0. The purified enzyme had apparent K-M and V-max values of 0.73 mM and 0.236 mu mol x min(-1), respectively. Al+3, Hg+2, Cu+2, Pb+2, and Cd+2 showed inhibitory effects on the enzyme. Pb+2 exhibited the strongest inhibitory action. Cd+2 and Hg+2 were moderate inhibitor, whereas Al+3 and Cu+2 showed weaker actions. All tested metals inhibited the enzyme in competitive manner. Our findings indicate that these metals inhibit the chicken enzyme in a similar manner to other alpha-CAs from mammals investigated earlier, but susceptibility to various metals differ between the native chicken and other mammalian enzymes.