Cleavage of fibrinogen by the human neutrophil neutral peptide-generating protease.

Abstract

The human neutrophil neutral peptide-generating protease, which generates a low molecular weight vasoactive peptide from a plasma protein substrate, is directly fibrinolytic and cleaves human fibrinogen in a manner distinct from plasmin. Fibrinogen was reduced from 340,000 Mr to derivatives of 270,000-325,000 Mr during interaction with the protease at enzyme-to-substrate ratios of 0.3 or 1.0 yg/1.0 mg.The 310,000-325,000 M, cleavage fragments exhibited prolonged thrombin-induced clotting activity but were able to be coagulated, whereas the 270,000-290,000 Mr fragments were not able to be coagulated. Anticoagulants were not generated at either enzyme dose. As analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis in 4-30% gradient gels and 10% gels stained for protein and carbohydrate, the diminution to 310,000-325,000 Mr and the prolongation of thrombin-induced clotting time resulted from cleavage of the fibrinogen Aa chain. The further decrease in size to 270,000-290,000

Bioinformatic analysis of protein structure–function relationships: case study of leukocyte elastase (ELA2) missense mutations

“…The HNE also acts extracellularly, particularly at sites of inflammation [Weiss, 1989]. The human neutrophil elastase degrades not only elastin, but also various other tissue proteins such as collagens, proteoglycans, and plasma factors like fibrinogen, fibrin, and antithrombin III [Wintroub et al, 1980;Bach-Gansmo et al, 1996;Gillis et al, 1997], and bacteria virulence proteins [Belaaouaj et al, 2000;Weinrauch et al, 2002]. A recently described novel mechanism explains how neutrophils release granule proteins and chromatin, which together form extracellular fibers to bind and kill bacteria [Brinkmann et al, 2004].…”

A human neutrophil-dependent pathway for generation of angiotensin II. Purification of the product and identification as angiotensin II.

“…In addition to generating angiotensin II from angiotensinogen, cathepsin G converts angiotensin I to angiotensin II (unpublished observations). Among the other substrates of cathepsin G are fibrin and fibrinogen (29,30). The fibrinolytic potential in concert with generation of angiotensin II suggests that the modulated expression of this system may facilitate inflammatory cell movement into a local tissue site by generation of a potent permeability factor which regulates local blood flow, and by local control of fibrin deposition.…”

“…The neutrophil enzyme is a neutral protease of 29,000-30,000 mol wt (2) that has been localized to the neutrophil granule by noncytotoxic release from cytocholasin-B treated human neutrophils and by subcellular fractionation of purified neutrophils (3). It is inhibited by a,-antitrypsin (1) and cleaves human fibrinogen and fibrin (29). The protease has been separated from leukocyte collagenase and elastase on the basis of physicochemical characteristics and synthetic substrate specificity (2).…”

Identification of a human neutrophil angiotension II-generating protease as cathepsin G.

“…J.) (8), SDS-gradient polyacrylamide gel electrophoresis (SDS-gradient PAGE) was carried out in 4-30% acrylamide gels (Pharmacia Fine Chemicals) as described (6). Immune and nonimmune goat IgG were purified as described (9).…”

“…Furthermore, the peptide product of the interaction of purified neutrophil protease and angiotensinogen is angiotensin II on the basis of its antigenic and physicochemical characteristics, and amino acid composition and sequence (5). The angiotensin II-generating human neutrophil protease, which is also fibrinogenolytic and fibrinolytic (6), is now identified as cathepsin G on the basis of subcellular localization, substrate specificity, and physicochemical and antigenic characteristics.…”