Identification of an antifreeze lipoprotein from Moraxella sp. of Antarctic origin.
We found six bacteria capable of producing antifreeze protein (AFP) from Ross Island, Antarctica. Among these AFP-producing bacteria, strain No. 82 had the highest antifreeze activity and was identified as Moraxella sp. The optimum temperature and pH for the production of AFP were 5 degrees C and 7.0, respectively. After partially purifying the AFP from the culture supernatant using 60% saturation of ammonium sulfate, only the 52-kDa protein band (100 microg/ml) which eluted from SDS-PAGE indicated antifreeze activity by the formation of hexagonal crystals. Furthermore, we confirmed that this AFP was a lipoprotein by the lipid stain test and treatment with some enzymes and that it had no ice-nucleating activity. Also, the N-terminal amino acid sequence of this AFP had high similarity with that of outer membrane proteins from Moraxella (Branhamella) catarrhalis. This is the first report of AFP-producing bacteria in Antarctica and an antifreeze lipoprotein (AFLP) from Moraxella sp.
Yamashita
Yasuhiro
Y
Department of Biotechnology, Faculty of Engineering, Kansai University, Suita, Osaka, Japan. gm9d606@ipcku.kansai-u.ac.jp
Nakamura
Norifumi
N
Omiya
Kazuhiro
K
Nishikawa
Jiro
J
Kawahara
Hidehisa
H
Obata
Hitoshi
H
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000864:Antarctic Regions; D021301:Antifreeze Proteins / Q000737:chemistry* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D008074:Lipoproteins / Q000737:chemistry* / Q000302:isolation & purification; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009016:Moraxella / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
D000596:Amino Acids; D021301:Antifreeze Proteins; D008074:Lipoproteins