Figure 5: (A) Effect of substrate concentration on the kinetics of Btae TX-I PLA2 activity. The graph showed a curvilinear shape at low substrate concentration. (B) Line weaver Burk’s plot of Btae TX-I. (C) Effect of pH on Btae TX-I activity. (D) Effect of temperature on the PLA2 activity of Btae TX-I. (E) Inhibition of Btae TX-I activity by crotapotin (CdtF5, CdtF7, CdcolF3 and CdcolF4) isolated from C. durissus terrificus and C. durissus collilineatus venom. (F) Influence of ions (10 mM each) on PLA2 activity in the absence or presence of 1 mM Ca2+ compared to Btae TX-I activity in the presence of 10 mM Ca2+. The results of all experiments are the mean ± S.E. of three determinations (p<0.05).