First Archaeal PEPB-Serine Protease Inhibitor fromSulfolobus solfataricuswith Noncanonical Amino Acid Sequence in the Reactive-Site Loop

2009 ◽  
Vol 8 (1) ◽  
pp. 327-334 ◽  
Author(s):  
Gianna Palmieri ◽  
Giuliana Catara ◽  
Michele Saviano ◽  
Emma Langella ◽  
Marta Gogliettino ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Protease Inhibitor ◽  
Serine Protease ◽  
Serine Protease Inhibitor ◽  
Reactive Site ◽  
Noncanonical Amino Acid

scholarly journals A novel locust (Schistocerca gregaria) serine protease inhibitor with a high affinity for neutrophil elastase

2006 ◽  
Vol 400 (3) ◽  
pp. 467-476 ◽  
Author(s):  
Michèle Brillard-Bourdet ◽  
Ahmed Hamdaoui ◽  
Eric Hajjar ◽  
Christian Boudier ◽  
Nathalie Reuter ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protease Inhibitor ◽  
Serine Protease ◽  
Neutrophil Elastase ◽  
Schistocerca Gregaria ◽  
Serine Protease Inhibitor ◽  
Cathepsin G ◽  
Human Neutrophil Elastase ◽  
Sequence Alignments ◽  
Putative Gene

We have purified to homogeneity two forms of a new serine protease inhibitor specific for elastase/chymotrypsin from the ovary gland of the desert locust Schistocerca gregaria. This protein, greglin, has 83 amino acid residues and bears putative phosphorylation sites. Amino acid sequence alignments revealed no homology with pacifastin insect inhibitors and only a distant relationship with Kazal-type inhibitors. This was confirmed by computer-based structural studies. The most closely related homologue is a putative gene product from Ciona intestinalis with which it shares 38% sequence homology. Greglin is a fast-acting and tight binding inhibitor of human neutrophil elastase (kass=1.2×107 M−1·s−1, Ki=3.6 nM) and subtilisin. It also binds neutrophil cathepsin G, pancreatic elastase and chymotrypsin with a lower affinity (26 nM≤Ki≤153 nM), but does not inhibit neutrophil protease 3 or pancreatic trypsin. The capacity of greglin to inhibit neutrophil elastase was not significantly affected by exposure to acetonitrile, high temperature (90 °C), low or high pH (2.5–11.0), N-chlorosuccinimide-mediated oxidation or the proteolytic enzymes trypsin, papain and pseudolysin from Pseudomonas aeruginosa. Greglin efficiently inhibits the neutrophil elastase activity of sputum supernatants from cystic fibrosis patients. Its biological function in the locust ovary gland is currently unknown, but its physicochemical properties suggest that it can be used as a template to design a new generation of highly resistant elastase inhibitors for treating inflammatory diseases.

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