Purification and characterization of a halotolerant intracellular protease from Bacillus subtilis strain FP-133
✍ Scribed by Endang Setyorini; Young-Ju Kim; Shinji Takenaka; Shuichiro Murakami; Kenji Aoki
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 123 KB
- Volume
- 46
- Category
- Article
- ISSN
- 0233-111X
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✦ Synopsis
Abstract
A halotolerant strain FP‐133, able to grow at concentrations of 0–12.5% (w/v) NaCl, was isolated from a fish paste and identified as Bacillus subtilis . B. subtilis strain FP‐133 produced an intracellular protease which showed catalytic activity under saline conditions. The enzyme was purified to homogeneity 143‐fold with a yield of 0.9%. The purified enzyme showed an optimum activity at a concentration of 5% (w/v) NaCl. After storage in 7.5% (w/v) NaCl at 4 °C for 24 h, the enzyme kept 100% of its activity. The molecular mass of the protease was determined to be 59 kDa by gel filtration; the protein consisted of four subunits each with a molecular mass of 14 kDa. The enzyme showed aminopeptidase activity. It acted on l‐leucyl‐p ‐nitroanilide, l‐leucyl‐β‐naphthylamide, and oligopeptides containing glycine, l‐histidine, or l‐leucine. The K~m~ and V ~max~ values for l‐leucyl‐p ‐nitroanilide were 18 µm and 2.2 mm/h mg, respectively. The enzyme was activated by Fe^2+^, Fe^3+^, and Ni^2+^ in synergism with Mg^2+^. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)