title: MALDI-TOF mass spectrometry analysis of substrate specificity of lebetase, a direct-acting fibrinolytic metalloproteinase from Vipera lebetina snake venom.
abstract: Lebetase is a direct-acting fibrinolytic zinc metalloendopeptidase related in amino acid sequence to reprolysins which include both hemorrhagic and non-hemorrhagic proteinases. Despite apparent structural similarities, fibrinolytic and hemorrhagic proteinases differ significantly in substrate specificity. In this study, we have examined the activity of lebetase I against biologically active peptides (bradykinin, kallidin, substance P) and 6-10 amino acid residues containing peptides synthesized according to cleavage regions of alpha(2)-macroglobulin, pregnancy zone protein (PZP) and fibrinogen. Lebetase was found to have no activity against studied hexapeptides. Surprisingly, the best substrates for lebetase were substance P, and peptide fragment of PZP, both were cleaved at position Pro-Gln. Identification of the hydrolysis products of 15 peptides by MALDI-TOF mass spectrometry analysis indicates that lebetase possesses broad substrate specificity. The MALDI-TOF MS technique was proven to be highly efficient for the recovery and identification of the peptides released by lebetase hydrolysis.
authors.affiliation: National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, Estonia.
authors.forename: K
authors.initials: K
authors.lastname: Trummal
authors.forename: H
authors.initials: H
authors.lastname: Vija
authors.forename: J
authors.initials: J
authors.lastname: Subbi
authors.forename: J
authors.initials: J
authors.lastname: Siigur
mesh_terms: D000818:Animals; D008666:Metalloendopeptidases / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D014757:Viper Venoms
chemical_list: D010455:Peptides; D014757:Viper Venoms; D008666:Metalloendopeptidases; C069853:lebetase