The bactericidal effect of human secreted group IID phospholipase A2 results from both hydrolytic and non-hydrolytic activities

► Three-site-directed active-site mutants of the hsPLA2GIID have been prepared using site-directed mutagenesis. ► All mutants have been successfully expressed and refolded to the native conformation. ► Bactericidal activity of the protein has been directly demonstrated. ► A calcium-independent (and hydrolysis independent) membrane-damaging effect of the enzyme is described. ► The hydrolysis independent membrane-damaging effect is relevant for the bactericidal mechanism of the protein.