Effects of Poly-L-lysine on Activities of Leukocyte Proteinases and on Release of Proteinases from Leukocytes

Abstract

Recently, polycations have been reported to activate the erythrocyte multicatalytic proteinase and release lactate dehydrogenase from endothelial cells. Furthermore, polycations seem to affect vascular permeability and prostaglandin synthesis in cultured glomerular mesangial cells. We previously reported the application of poly-L-lysine for the purification of leukocyte cathepsin G (CLP) by affinity chromatogaphy and the effect of polycations on the amidolytic activities of leukocyte elastase (ELP) and CLP.In this study, we also found that at a low concentration, poly-L-lysine stimulated the release of ELP and CLP from leukocytes.1) At a concentration of 1.5μM, poly-L-lysine (mw. 290, 000) stimulated the release of ELP and CLP from separated leukocytes in the same extent as 2M NaCl.2) Poly-L-lysine (mw. 290, 000) stimulated the release of CLP and ELP from leukocytes in diluted blood at a concentration of 5 and 10nM, respectively. On the other hand, a several times higher concentration of poly-L-lysine was required for release of both enzymes from leukocytes in non-diluted blood.3) In proportion to molecular weight, poly-L-lysine enhanced amidolytic activities of ELP and CLP and the fibrinolytic activity of ELP. Thus, poly-L-lysine enhanced the activity of ELP at a lower concentration than activity of CLP.