title: Purification and characterization of a trypsin-like enzyme with fibrinolytic activity present in the abdomen of horn fly, Haematobia irritans irritans (Diptera: Muscidae).
abstract: This work describes the purification and characterization of a trypsin-like enzyme with fibrinolytic activity present in the abdomen of Haematobia irritans irritans (Diptera: Muscidae). The enzyme was purified using a one-step process, consisting of affinity chromatography on SBTI-Sepharose. The purified protease showed one major active proteinase band on reverse zymography with 0.15% gelatin, corresponding to a molecular mass of 25.5 kDa, with maximum activity at pH 9.0. The purified trypsin-like enzyme preferentially hydrolyzed synthetic substrates with arginine residue at the P1 position. The Km values determined for three different substrates were 1.88 x 10(-4), 1.28 x 10(-4), and 1.40 x 10(-4) M for H-alpha-benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide (S2222), DL-Ile-Pro-Arg-p-nitroanilide (S2288), and DL-Phe-Pip-Arg-p-nitroanilide (S2238), respectively. The enzyme was strongly inhibited by typical serine proteinase inhibitors such as SB
authors.affiliation: Departamento de Bioquímica, Universidade Federal de São Paulo, Escola Paulista de Medicina, SP, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Dametto
authors.forename: A P
authors.initials: AP
authors.lastname: David
authors.forename: S S
authors.initials: SS
authors.lastname: Azzolini
authors.forename: I T
authors.initials: IT
authors.lastname: Campos
authors.forename: A M
authors.initials: AM
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Gomes
authors.forename: R
authors.initials: R
authors.lastname: Andreotti
authors.forename: A S
authors.initials: AS
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D005337:Fibrin / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009117:Muscidae / Q000201:enzymology* / Q000378:metabolism; D012697:Serine Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D005343:Fibrinolytic Agents; C114880:trypsin-like serine protease; D005337:Fibrin; D012697:Serine Endopeptidases