Improvement of Thermostability of a Calcium-free .ALPHA.-Amylase from an Alkaliphilic Bacillus sp. by Protein Engineering.
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چکیده
منابع مشابه
Crystal structure of calcium-free alpha-amylase from Bacillus sp. strain KSM-K38 (AmyK38) and its sodium ion binding sites.
The crystal structure of a calcium-free alpha-amylase (AmyK38) from Bacillus sp. strain KSM-K38, which resists chelating reagents and chemical oxidants, has been determined by the molecular replacement method and refined to a crystallographic R-factor of 19.9% (R-free of 23.2%) at 2.13-A resolution. The main chain folding of AmyK38 is almost homologous to that of Bacillus licheniformis alpha-am...
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An alkaliphilic and highly thermostable α-amylase producing Bacillus sp. was isolated from Van soda lake. Enzyme synthesis occurred at temperatures between 25°C and 40°C. Analysis of the enzyme by SDS-PAGE revealed a single band which was estimated to be 66 kDa. The enzyme was active in a broad temperature range, between 20°C and 90°C, with an optimum at 50°C; and maximum activity was at pH 10....
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The capacity of ribosomal modification to improve antibiotic production by Streptomyces spp. has already been demonstrated. Here we show that introduction of mutations that produce streptomycin resistance (str) also enhances alpha-amylase (and protease) production by a strain of Bacillus subtilis as estimated by measuring the enzyme activity. The str mutations are point mutations within rpsL, t...
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A novel liquefying alpha-amylase (LAMY) was found in cultures of an alkaliphilic Bacillus isolate, KSM-1378. The specific activity of purified LAMY was approximately 5,000 U mg of protein-1, a value two- to fivefold greater between pH 5 and 10 than that of an industrial, thermostable Bacillus licheniformis enzyme. The enzyme had a pH optimum of 8.0 to 8.5 and displayed maximum activity at 55 de...
متن کاملA calcium-dependent xylan-binding domain of alkaline xylanase from alkaliphilic Bacillus sp. strain 41M-1.
Xylanase J of alkaliphilic Bacillus sp. strain 41M-1 contains a carbohydrate-binding module family 36 xylan-binding domain (XBD). Mutational analysis of the XBD revealed that Tyr237, Asp313, Trp317, and Asp318 were involved in Ca(2+)-dependent xylan-binding, and that Asp313 and Asp318 were especially important.
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ژورنال
عنوان ژورنال: Journal of Applied Glycoscience
سال: 2002
ISSN: 1344-7882,1880-7291
DOI: 10.5458/jag.49.281