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

Figures & data

Figure 1. SDS-polyacrylamide gel electrophoresis of the gill CA (line 1: purified sturgeon gill CA, line 2: the homogenate of sturgeon gill, line 3: standard proteins).

Table 1. Purification of sturgeon gill CA by affinity chromatography.

	Total volume (mL)	Activity (EU/mL)	Total activity (EU)	Protein (mg/mL)	Total protein (mg)	Specific activity (EU/mg protein)	Yield (%)	Purification fold
Crude enzyme	44	22	968	6.5	286.0	3.4	100	1
Affinity chromatography	5	40	200	0.18	0.9	222.2	20.7	66

Table 2. Kinetic parameters of the sturgeon gill CA in the presence of 4-nitrophenyl acetate (pNPA) as a substrate.

Substrate	Optimum pH	Optimum temperature (°C)	Vmax (μM/min)	Km (mM)	kcat (s^−1)	kcat/Km (mM^−1s^−1)
p-NPA	6.0	35	5 × 10^6	2.5	134 408.6	53 763.4

Table 3. In vitro inhibition of some metal ions and sulfonamides against the hydratase activity of sturgeon gill CA.

Inhibitor	IC50* (μM)
Acetazolamide	0.1
Sulfanilamide	13.0
Co^2+	1700
Zn^2+	1100
Ni^2+	1200
Fe^2+	200
Cu^2+	800
Ba^2+	1100

*Molarity of inhibitor producing a 50% decrease of enzyme activity.