Fig. 6. pH dependence of the PAF phosphorylcholine hydrolase activity of Culex quinquefasciatus SGH. The amount of PAF hydrolyzed at the indicated times (0, 30 and 60 min) of incubation and pH are indicated. Other conditions are as in Fig. 2, except that the ammonium acetate buffer was adjusted with acetic acid or ammonia to the indicated pH.