title: An arginine specific protease from Spirulina platensis.
abstract: An arginine specific protease, Sp-protease, was purified by column chromatography from freeze-dried Spirulina platensis using a five-step process. Purified Sp-protease has a molecular weight of 80 kDa. It hydrolyzed the synthetic substrates containing arginine residue in the P1 position but did not hydrolyze synthetic substrates containing other amino acid residues, including lysine residue in the P1 position. Among the synthetic substrates tested, a substrate of plasminogen activator (Pyr-Gly-Arg-MCA) was hydrolyzed most effectively with the enzyme (Km = 5.5 x 10(-6) M), and fibrin gel was solubilized via activation of intrinsic plasminogen to plasmin with the enzyme. Activity was inhibited completely with camostat mesilate (Ki = 1.1 x 10(-8) M) and leupeptin (Ki = 3.9 x 10(-8) M) but was not inhibited with Nalpha-tosyl-L-lysine chloromethyl ketone (TLCK). The optimum pH of the enzyme has a range of pH 9.0 to pH 11.0. The optimum temperature was 50 degrees C; the enzyme was stable at 0-50 degrees C.
authors.affiliation: Department of Biomedical Engineering, Toin University of Yokohama, Toin Human Science and Technology Center, 1614, Yokohama, 225-8502, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Yada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nagata
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Yoh
authors.initials: Y
authors.lastname: Kodera
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nishimura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Inada
authors.forename: Ayako
authors.initials: A
authors.lastname: Matsushima
mesh_terms: D000458:Cyanobacteria / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D010450:Endopeptidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D005337:Fibrin / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008970:Molecular Weight; D010958:Plasminogen / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D020539:Sequence Analysis, Protein; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D011480:Protease Inhibitors; D005337:Fibrin; D010958:Plasminogen; D010450:Endopeptidases; C034735:arginine protease