Purification and biochemical characterization of a novel carbonic anhydrase II from erythrocytes of camel (Camelusdromedarius).

A novel carbonic anhydrase II (CA II) from erythrocytes of camel (Camelus dromedarius) was purified to homogeneity using affinity chromatography and biochemically characterized. Specific activity of 140.88 U/mg was obtained with 745.17-fold purification and 25.37% yield. The enzyme was a monomer with a lower molecular weight (25 kDa) and lower Zn content (0.50 mol of Zn per mol of protein). The enzyme showed higher optimum temperature (70 °C) and pH (pH 9.0), moreover, it was stable at higher temperatures and strongly alkaline pH as judged by thermodynamic parameters (E, k, E, t, D-value, Z-value, ΔH, ΔG and ΔS). The enzyme was inhibited by cations (Al, Ca, Cd, Co, Cr, Cu, Fe, Ni, Mg and Zn) as well as by anions (Br, CHCOO, ClO, CN, F, HCO, I, N, NO and SCN), some anions (CHO, CO, SeO and SO) does not affect enzyme activity. Effect of various chemicals on enzyme activity was also investigated. K, V, k and k/K values for 4-NPA were found to be 1.74 mM, 0.0093 U/mL, 0,0039 s and 0,0023 s mM, respectively. With these interesting biochemical properties, camel CA II represents promising candidate for harsh industrial applications, in particular, for a successful biomimetic CO sequestration process.