Figure 7. The optimal pH of (A) V. affinis venom hyaluronidase and (B) wild-type and mutant rVesA2. (A) The crude venom showed relatively high hyaluronidase activity at low and neutral pH. (B) The wild-type rVesA2 showed activity at pH 2-3 and completely lost its activity at pH 4 (blue line). The mutant rVesA had no enzymatic activity (red line).