Cathepsin L inactivates alpha 1-proteinase inhibitor by cleavage in the reactive site region.

Limited proteolysis by macrophage elastase inactivates human alpha 1- proteinase inhibitor

Inflammatory mouse peritoneal macrophages secrete a metalloproteinase that is not inhibited by alpha 1-proteinase inhibitor. This proteinase, macrophage elastase, recognizes alpha 1-proteinase inhibitor with macrophage elastase does not involve a stable proteinase-inhibitor complex and results in the proteolytic removal of a peptide of apparent molecular weight 4,000-5,000 from the inhibitor. A...

Alpha 1-proteinase inhibitor (human) shortage.

Mapping the extended substrate binding site of cathepsin G and human leukocyte elastase. Studies with peptide substrates related to the alpha 1-protease inhibitor reactive site.

The kinetic constants for the hydrolysis of a series of I-nitroanilide substrates by human leukocyte (HL) elastase and cathepsin G, porcine pancreatic elastase, and bovine chymotrypsin at pH 7.50 are reported. HL elastase and cathepsin G are currently thought to be the agents responsible for destruction of the lung in the disease emphysema. MeO-Sue-Ala-Ala-Pro-VaI-NA is an excellent substrate f...

Cathepsin S. The cysteine proteinase from bovine lymphoid tissue is distinct from cathepsin L (EC 3.4.22.15).

Cathepsin S was purified from bovine spleen by acid autolysis, (NH4)2SO4 fractionation and chromatography on CM-Sephadex C-50, CM-cellulose and activated-thiol-Sepharose. Cathepsin L was isolated from lysosomal fractions of rat liver, rat kidney and bovine liver. Generally, cathepsin L was bound tightly to CM-Sephadex C-50. Preparations of cathepsin L from rat liver, rat kidney and bovine liver...

Plasminostreptin, a protein proteinase inhibitor produced by Streptomyces antifibrinolyticus. II. Determination of the reactive site for proteinases.

Chemical modification of the amino groups of plasminostreptin with 2,4,6-trinitrobenzene sulfonic acid or O-methylisourea completely abolished its inhibitory activities against trypsin (EC 3.4.21.4) and plasmin (EC 3.4.21.7). This indicated that plasminostreptin requires at least 1 lysine residue for its trypsin and plasmin inhibitory activities. Incubation of plasminostreptin with a small amou...