Purification and characterization of two novel halotolerant extracellular proteases from Bacillus subtilis strain FP-133.
Bacillus subtilis strain FP-133, isolated from a fermented fish paste, synthesized two novel halotolerant extracellular proteases (expro-I and expro-II), showing activity and stability at concentrations of 0-20% (w/v) NaCl. Each protease was purified to homogeneity and characterized. The purified expro-I was a non-alkaline serine protease with an optimum pH of 7.5, although most serine proteases from Bacillus strains act at the alkaline side. The molecular mass of expro-I was 29 kDa. The purified expro-II was a metalloprotease with a molecular mass of 34 kDa. It was activated by Fe(2+), which has never been reported as a bacterial protease activator. At a concentration of 7.5% (w/v) NaCl, both proteases preferred animal proteins to vegetable proteins as natural substrates. In addition, under saline conditions, expro-I and II showed high catalytic activity toward gelatin and casein respectively.
Division of Life Science, Graduate School of Science and Technology, Kobe University, Japan.
Endang
E
Setyorini
Shinji
S
Takenaka
Shuichiro
S
Murakami
Kenji
K
Aoki
D001412:Bacillus subtilis / Q000187:drug effects / Q000201:enzymology*; D002244:Carbon / Q000494:pharmacology; D002384:Catalysis / Q000187:drug effects; D002412:Cations / Q000737:chemistry; D017077:Culture Media, Conditioned; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000737:chemistry / Q000494:pharmacology; D008970:Molecular Weight; D009584:Nitrogen / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000302:isolation & purification* / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D011489:Protein Denaturation; D012965:Sodium Chloride / Q000494:pharmacology*; D013379:Substrate Specificity; D013696:Temperature
D002412:Cations; D017077:Culture Media, Conditioned; D008670:Metals; D011480:Protease Inhibitors; D012965:Sodium Chloride; D002244:Carbon; D010447:Peptide Hydrolases; D009584:Nitrogen