Priming effect of N-acetyl-S-(3-oxo-3-carboxy-n-propyl)cysteine in human neutrophils and tyrosyl phosphorylation of 45 kDa protein

Human peripheral blood polymorphonuclear leukocytes were preincubated with N-acetylcystathionine and N-acetyl-S-(3-oxo-3-carboxy-n-propyl)cysteine (NAc-OCPC) found in the urine of a patient with cystathioninuria. NAc-OCPC significantly enhanced the N-formylmethionyl-leucyl-phenylalanine-induced superoxide generation, whereas N-acetylcystathionine did not enhance the superoxide generation. When the cells were incubated with NAc-OCPC, the tyrosyl phosphorylation of 45 kDa protein of the cell was markedly increased with time. The phosphorylation process was dependent on the concentration of NAc-OCPC. Both the superoxide generation and the tyrosyl phosphorylation of 45 kDa protein increased by NAc-OCPC were inhibited by genistein and herbimycin A, the inhibitors of protein tyrosine kinase, but were rather enhanced by staurosporine, an inhibitor of protein kinase C. (C) 1997 Elsevier Science B.V.