Zn2+-binding to the wild-type and mutant BLT1. Mag-fura 2-monitored Zn2+ binding to BLT1 (open squares), BLT1V119H (open circles), BLT1R218H, T219H (closed squares), and BLT1V119H, R218H, T219H (closed circles). The data are presented as the amount of Zn2+ bound per receptor molecule (molar Zn2+-to-BLT1 ratio) as a function of Zn2+ concentration. Data represent the mean SE from three independent experiments.