ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract Alkaline protease (EC 3.4.21.14) activity, suitable for use in detergents, was detected in the alkaline culture medium of Bacillus sp. KSM-K16, which was originally isolated from soil. The enzyme, designated M protease, was purified to homogeneity from the culture broth by column chromatographies. The N-terminal amino acid sequence was Ala–Gln–Ser–Val–Pro–Trp–Gly–Ile–Ser–Arg–Val–Gln–Ala–Pro–Ala–Ala–His–Asn–Arg–Gly–Leu–Thr–Gly. The molecular mass of the protease was 28 kDa, and its isoelectric point was close to pH 10.6. Maximum activity toward casein was observed at 55 °C and at pH 12.3 in 50 mM phosphate/NaOH buffer. The activity was inhibited by phenylmethylsulfonyl fluoride and chymostatin. The enzyme was very stable in long-term incubation with liquid detergents at 40 °C. The enzyme cleaved the oxidized insulin B chain initially at Leu15–Tyr16 and efficiently at ten more sites. Among various oligopeptidyl p-nitro-anilides (pNA) tested, N-succinyl-Ala-Ala-Pro-Phe-pNA was efficiently hydrolyzed by M protease. M protease was precipitated in (NH4)2SO4-saturated acetate buffer (pH 5.0) as plank-like crystals.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002530050437
Permalink