ABSTRACT
Negative electrostatic potential at membrane surface is essential for membrane binding and activation of cationic enzymes, such as secretory phospholipase A2 (PLA2) [2,4,9,10]. Addition of acidic lipids or detergents to zwitterionic lipid membranes substantially increases the binding and activity of secretory PLA2s [2,10], and mutations of one or more Lys residues of the enzyme suppressed its membrane binding and activity [9,42]. These results strongly imply that the electrostatic interactions between the basic residues of secretory PLA2s and the acidic lipids of the membrane play key roles in both membrane binding and activity of the enzyme.
