Characterization of carbonic Aanhydrase from Russian sturgeon fish (Acipenser gueldenstaedtii)

In this study, carbonic anhydrase enzymes (CA) from Russian Sturgeon Fish (Acipenser gueldenstaedtii) tissues have been characterized. The hydratase activity of carbonic anhydrase in extract from heart, brain, gill and erythrocyte hemolyzates of the fish was determined as 2.5, 7.4, 5.2, 10.8 EU / mg protein, respectively. Carbonic anhydrase from the fish gill was purified 66-fold, as yield 222.2, and specific activity 20.7 EU / mg protein using Sepharose-4B-L tirosine-sulfanilamide affinity column.The purity of the enzyme was decided to be observed a single protein band on sodium dodesilsülfat polyacrylamide gel (SDS-PAGE) electrophoresis. As a result of SDS-PAG electrophoresis; the purified carbonic anhydrase in the gills of Russian Sturgeon Fish (Acipenser gueldenstaedtii) subunit molecular mass is about 20 kDa. Esterase activity of the enzyme in the presence of the substrate p-nitrophenyl acetate, was found to be the highest at pH 6.0 and a temperature of 40°C. KM and Vmaks kinetic values for gill carbonic anhydrase was calculated by a Lineweaver-Burk graph using p-nitrophenol acetate (p-NPA) as a substrate, and was defined as 2.5 mM and 5x106 ? M/min, respectively. Kcat and Kcat/KM values indicating that the enzyme the effectiveness of against p-NFA were found as 134408.6 s-1 and 53763.4 mM-1s-1. CA from its gill has very low IC50 values such as 13.0 and 0.1 ? M in the presence of the sulfanilamide and acetazolamide as inhibitors, was found. In addition, the enzyme were determined to be inhibited with the IC50 values as 1.1 mM in the presence of Zn +2 and Ba +2, 0.2 mM in the presence of Fe +2, 1.7 mM in the presence of Co +2 and 1.2 mM in the presence of Ni +2.Key words: Carbonic Anhydrase, Russian Sturgeon, Acipenser gueldenstaedtii