title: Purification and characterization of alkaline serine proteinase from photosynthetic bacterium, Rubrivivax gelatinosus KDDS1.
abstract: In order to reduce the protein content of wastewater, photosynthetic bacteria producing proteinases were screened from wastewater of various sources and stocked in culture. An isolated strain, KDDS1, was identified as Rubrivivax gelatinosus, a purple nonsulfur bacterium that secretes proteinase under micro-aerobic conditions under light at 35 degrees C. Molecular weight of the purified enzyme was estimated to be 32.5 kDa. The enzyme showed the highest activity at 45 degrees C and pH 9.6, and the activity was completely inhibited by phenylmethyl sulfonyl fluoride (PMSF), but not by EDTA. The amino-terminal 24 amino acid sequence of the enzyme showed about 50% identity to those of serine proteinases from Pseudoalteromonas piscicida strain O-7 and Burkholderia pseudomallei. Thus, the enzyme from Rvi. gelatinosus KDDS1 was thought to be a serine-type proteinase. This was the first serine proteinase characterized from photosynthetic bacteria.
authors.affiliation: Department of Applied Biology, Kyoto Institute of Technology, Japan. bika@ipc.kit.ac.jp
authors.forename: Kohei
authors.initials: K
authors.lastname: Oda
authors.forename: Somporn
authors.initials: S
authors.lastname: Tanskul
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oyama
authors.forename: Napavarn
authors.initials: N
authors.lastname: Noparatnaraporn
mesh_terms: D000595:Amino Acid Sequence; D020562:Betaproteobacteria / Q000201:enzymology*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D012244:Rhodospirillaceae / Q000201:enzymology* / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000378:metabolism; D013696:Temperature
chemical_list: D015842:Serine Proteinase Inhibitors; D012697:Serine Endopeptidases