Fig. 3. Electrostatic properties and effect of salt on
enzymatic activity of mCA XIV. (a) The surface electrostatic
potentials, the decrease in electrostatic free energy on
transfer from 3.0 to 0.1 M NaCl, and surface density of acidic
and basic residues are as described in Fig. 2. (b and c) Assays
of CO hydration activity (b) and ester hydrolysis activity
(c) of dCA II (green), mCA XIV (yellow), or hCA I (red) were
performed as described in Materials and Methods. Controls
indicate enzyme activity in the absence of salt. For esterase
activity, 0.5 mM p-nitrophenyl acetate was used as substrate.
Pot, electrostatic potential.