muramidase and 1-2-epoxy-3-(p-nitrophenoxy)propane

Two active site inhibitors of acid proteinases were tested for their effects on human neutrophil chemotaxis and lysosomal enzyme release. Both bromphenacyl bromide (BPAB) and epoxy-p-nitrophenoxypropane (EPNP) inhibited chemotaxis and chemotaxin-induced enzyme release elicited by pepstatin and formylmethionyl peptides, which share membrane receptors, and also by zymosan-activated serum, the major active component of which (C5a) occupies a different receptor. In contrast to the previously tested acid protease inhibitor diazoacetylnorleucine methyl ester, neither BPAB nor EPNP blocked binding of [3H]fMLP to neutrophils. Thus BPAB and EPNP inhibit chemotaxin-mediated neutrophil functions, but not by interaction with the chemotaxin receptor.

Topics: Acetophenones; Acid Phosphatase; Chemotaxis, Leukocyte; Dipeptides; Epoxy Compounds; Humans; Lysosomes; Muramidase; N-Formylmethionine; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Nitrophenols; Oligopeptides; Pepstatins; Protease Inhibitors