InhA-like protease secreted by Bacillus sp. S17110 inhabited in turban shell.
A strain producing a potent protease was isolated from turban shell. The strain was identified as Bacillus sp. S17110 based on phylogenetic analysis. The enzyme was purified from culture supernatant of Bacillus sp. S17110 to homogeneity by ammonium sulfate precipitation, SP-Sepharose, and DEAE-Sepharose anion exchange chromatography. Protease activity of the purified protein against casein was found to be stable at pH 7 to pH 10 and around 50 degrees . Approximately 70% of proteolytic activity of the enzyme was detected either in the presence of 100 mM SDS or Tween 20. The enzyme activity was enhanced in the presence of Ca2+, Zn2+, Mg2+, but was inhibited by EDTA, indicating that it requires metal for its activity. The purified enzyme was found to be a monomeric protein with a molecular mass of 75 kDa, as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography. The purified enzyme was analyzed through peptide fingerprint mass spectra generated from matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) and a BLAST search, and identified as immune inhibitor A (inhA) deduced from nucleotide sequence of B. cereus G9241. Since InhA was identified as protease that cleave antibacterial proteins found in insect, inhA-like protease purified from Bacillus sp. S17110 might be pathogenic to sea invertebrates.
Jung
Sang Chul
SC
Department of Biological Sciences, College of Natural Science, Sunchon National University, Jeonnam, Republic of Korea.
Paik
Hyoung-Rok
HR
Kim
Mi Sun
MS
Baik
Keun Sik
KS
Lee
Woo-Yiel
WY
Seong
Chi Nam
CN
Choi
Sang Ki
SK
D000595:Amino Acid Sequence; D000818:Animals; D001407:Bacillus / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology; D049851:Gastropoda / Q000382:microbiology*; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D011480:Protease Inhibitors / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013816:Thermodynamics
D001426:Bacterial Proteins; D002413:Cations, Divalent; D010446:Peptide Fragments; D011480:Protease Inhibitors; D010447:Peptide Hydrolases