pH-Dependent properties of copolymers. A, zeta potential of copolymers, P/LOEt, P/LLL,P/III,P/WWW,PLWL, and P/FFF at pH 5.0 (gray bar) and 7.4 (striped bar). B, representative base titration of PMLA, P/LOEt(40%) and P/LLL (40%) with 0.5 N NaOH. pKa values were obtained from the titration curves as described under Methods. For the titration of PMLA (□) and P/LOEt (o) only single pKa(1)s were identified, while for P/LLL (◊) pKa(1) and pKa(2) were indicated. C, pH-dependence of membranolysis induced by copolymers P/LOEt(40%) (Δ), P/LLL (40%) (◊), P/L(d)LL(40%) (○), and P/WWW (40%) (□) at 50 µg/ml. Data represent means +SEM in triplicate.