Characterization of a novel elastase inhibitor from a fan coral.
An acidic hydromethanolic extract of the tropical gorgonian Melithea cf. stormii exhibited anti-elastase activity. From the polypeptidic mixture we isolated and purified to homogeneity a protein with a molecular mass determined at 21,159 Da by Maldi/Tof mass spectrometric analysis. The novel protein of marine invertebrate origin strongly inhibited amidolysis of Suc(Ala) 3pNA by porcine pancreatic elastase (PPE) and was labelled iela melst. The N-terminal aminoacid sequence of its 39-first residues revealed the characteristics of a non-classical Kazal-type domain. Iela melst behaved as a reversible tight-binding inhibitor of PPE. The competitive inhibition followed Cha's mechanism A with an equilibrium dissociation constant, Ki, calculated as 1.5 x 10(-9) M.
La Barre
S
S
Laboratoire de chimie, URA 401 CNRS, Paris, France.
Longeon
A
A
Barthélémy
M
M
Guyot
M
M
Le Caer
J P
JP
Bargibant
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D008969:Molecular Sequence Data; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D010443:Peptide Chain Termination, Translational
D010196:Pancreatic Elastase