title: A halophilic serine proteinase from Halobacillus sp. SR5-3 isolated from fish sauce: purification and characterization.
abstract: A halophilic bacterium was isolated from fish sauce, classified, and named Halobacillus sp. SR5-3. A purified 43-kDa proteinase produced by this bacterium showed optimal activity at 50 degrees C and pH 9-10 in 20% NaCl. The activity of the enzyme was enhanced about 2.5-fold by the addition of 20-35% NaCl, and the enzyme was highly stabilized by NaCl. It was found to be a serine proteinase related to either chymotrypsin or subtilisin. It absolutely preferred Ile at the P(2) position of substrates. Thus, the enzyme was found to be a halophilic serine proteinase with unique substrate specificity.
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok.
authors.forename: Sirilak
authors.initials: S
authors.lastname: Namwong
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hiraga
authors.forename: Katsumi
authors.initials: K
authors.lastname: Takada
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tsunemi
authors.forename: Somboon
authors.initials: S
authors.lastname: Tanasupawat
authors.forename: Kohei
authors.initials: K
authors.lastname: Oda
mesh_terms: D000595:Amino Acid Sequence; D001406:Bacillaceae / Q000145:classification / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D005396:Fish Products / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D012697:Serine Endopeptidases / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D013379:Substrate Specificity; D013785:Thailand
chemical_list: D004791:Enzyme Inhibitors; D012965:Sodium Chloride; D012697:Serine Endopeptidases