title: Purification and properties of a new psychrophilic metalloprotease (Fpp2) in the fish pathogen Flavobacterium psychrophilum.
abstract: To go further into the characterization of the proteolysis exocellular system of the salmonid pathogen Flavobacterium psychrophilum, the purification and characterization of a novel protease designated Fpp2 (F. psychrophilum protease 2) was undertaken. A protease (Fpp2) hydrolyzing azocasein was purified. The Fpp2 can be defined as a metalloprotease, it had an estimated molecular mass of 62 kDa with calcium playing an important role in the thermostability of the enzyme. Proteolytic activity was optimal at pH 6.0-7.0 and 24 degrees C and activation energy for the hydrolysis of azocasein was determined to be 5.4 kcal mol(-1), being inactive at temperatures above 42 degrees C. All these results are characteristic of 'cold adapted enzymes'. Fpp2 proved to be a broad range hydrolytic enzyme because in optimal conditions it was able to hydrolyze matrix and muscular proteins. It can be concluded that the Fpp1, a previously characterized 55 kDa metalloprotease, and the Fpp2 protease were produced under different physiological conditions and were immunologically as well as biochemically different.
authors.affiliation: Area de Microbiologia, Departamento de Biologi;a Funcional, Facultad de Medicina, IUBA, Universidad de Oviedo, 33006 Oviedo, Asturias, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Secades
authors.forename: B
authors.initials: B
authors.lastname: Alvarez
authors.forename: J A
authors.initials: JA
authors.lastname: Guijarro
mesh_terms: D002118:Calcium / Q000378:metabolism; D002364:Caseins / Q000378:metabolism; D002845:Chromatography / Q000379:methods; D004791:Enzyme Inhibitors / Q000032:analysis; D004795:Enzyme Stability; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005417:Flavobacterium / Q000201:enzymology* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D045726:Metalloproteases / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism*; D008970:Molecular Weight; D009124:Muscle Proteins / Q000378:metabolism; D013696:Temperature
chemical_list: D002364:Caseins; D004791:Enzyme Inhibitors; D016326:Extracellular Matrix Proteins; D009124:Muscle Proteins; C026018:azocasein; D045726:Metalloproteases; D002118:Calcium