Bactericidal properties of group IIA and group V phospholipases A(2)

Group V phospholipase A(2) (PLA(2)) is a recently characterized 14-kDa secr etory PLA(2) of mammalian heart and macrophage-derived cells. Group IIA PLA (2), which is structurally close to group V PLA(2), has been shown to kill Gram-positive bacteria in vitro and to prevent symptoms of Gram-positive in fection in vivo. We studied the antibacterial properties of fully active re combinant rat group IIA and V PLA(2)s. Both group IIA and V PLA(2)s were hi ghly bactericidal against Gram-positive bacteria, including methicillin-res istant staphylococci and vancomycin-resistant enterococci. Only high concen trations of group IIA PLA(2) showed some bactericidal effect against the Cr am-negative bacterium Escherichia coli, Our results confirm that group IIA PLA, is a potent antibacterial enzyme against Gram-positive bacteria, Moreo ver, we show here that group V PLA, is a novel antibacterial mammalian prot ein, but is less potent than group IIA PLA(2), Both enzymes may be consider ed as future therapeutic agents against bacterial infections.