PubMedDate not supplied
A high level of the membrane-bound proteinase (LMP) secretion by human polymorphonuclear leukocytes (up to 680 nmol/min/ml with N-benzoyl-L-arg-EE as a substrate) was shown during the cell adhesion to receptor-dependent (immobilized aggregates of IgG and C3b) and receptor-independent (DEAE-Sephadex and polymethyl methacrylate) absorbents. Incubation medium contained 6.10(6) cells/ml. The rate of secretion reached the maximal level during 15 min although its level was already high to the 5 min of C3b- and hydrophobic surface-induced activation (491 +/- 55 and 382 nmol/min, respectively). The high level of LMP secretion coincided with the peak of luminol-dependent chemoluminescence during the receptor-dependent adhesion, but did not correlate with a low level of luminescence in the receptor-independent adhesion. Localization of LMP in latent form in neutrophil membrane was shown earlier; the enzyme activation may occur due to effect of polycationic molecules of bovine tissue proteinase inhibitor of Kunitz type, protamine sulfate, alkaline fraction of ampholines. The enzyme (with BAEE as a substrate) was identified as serine proteinase of the trypsin-like type which activated Hageman factor (the XII factor of clotting system) and demonstrated the kininogenase activity. Only slight elastase-like activity was detected after incubation of neutrophils with all the adsorbents studied (0-2 nmol/min/ml with MeOSucAlaAlaProValpNA as a substrate). Chymotrypsin-like activity achieved maximum only by 30 min of activation with all the types of adsorbents (up to 270 nmol/min/ml with N-benzoyl-Tyr-EE as a substrate); this suggests impairment of azurophilic granules and appearance of cathepsin G.(ABSTRACT TRUNCATED AT 250 WORDS)