Characterization and inhibition studies of carbonic anhydrase from gill of Russian Sturgeon Fish (Acipenser gueldenstaedtii)

Abstract

An α-carbonic anhydrase (CA, EC 4.2.1.1) was purified and characterized kinetically from gill of Acipenser gueldenstaedtii as an endangered sturgeon species. The carbonic anhydrase was purified 66-folds with yield 20.7% by Sepharose-4B-l-tyrosine-sulfanilamide affinity column and the specific activity was determined as 222.2 EU/mg protein. K_m and V_max kinetic values for gill carbonic anhydrase were calculated by a Lineweaver–Burk graph using p-nitrophenol acetate (p-NPA) as a substrate, and was defined as 2.5 mM and 5 × 10⁶μM/min, respectively. It was observed that CA from the sturgeon gill in the presence of the sulfanilamide and acetazolamide as an inhibitor had very low IC₅₀ values such as 13.0 and 0.1 μM, respectively. In addition, it was determined that the enzyme was inhibited by Fe^2+, Co^2+, Ni²⁺, and Zn²⁺–Ba²⁺ with the IC₅₀ values of 0.2, 1.7, 1.2, and 1.1 mM, respectively.

• Acipenser gueldenstaedtii
• carbonic anhydrase
• Russian Sturgeon
• gill

Declaration of interest

This work was financially supported by the Recep Tayyip Erdoğan University.