Hyperthermostable mutants of Bacillus licheniformis alpha-amylase: thermodynamic studies and structural interpretation
نویسندگان
چکیده
منابع مشابه
thermodynamic and kinetic characteristics of an α-amylase from Bacillus licheniformis SKB4
An amylolytic bacterial strain, Bacillus licheniformis SKB4 produced maximum amylase at pH 6.5 at 42 °C, and at late stationary phase (24 h) of growth. Starch and peptone were found the best supporting carbon and nitrogen source with C:N ratio of 1:2 for amylase production. The purified enzyme was non-responsive to most of the metal ions except K+ and Mg++ (1.0 mM). The enzyme was stable and ac...
متن کاملKinetics and Thermodynamic Studies of Alpha Amylase from Bacillus Licheniformis Mutant Ikram-ul-haq*, Muhammad Mohsin Javed, Uzma Hameed and Fazal Adnan
The present investigation deals with the purification and characterization of enzyme α-amylase from a mutant strain of Bacillus licheniformis EMS-6. A laboratory scale stirred fermentor of 7.5 L capacity was used for the enzyme production under optimal conditions. The enzyme was purified up to homogeneity level by Ammonium sulphate and ion-exchange chromatography using a fast protein liquid chr...
متن کاملStructural genes encoding the thermophilic alpha-amylases of Bacillus stearothermophilus and Bacillus licheniformis.
The genes encoding the thermostable alpha-amylases of Bacillus stearothermophilus and B. licheniformis were cloned in Escherichia coli, and their DNA sequences were determined. The coding and deduced polypeptide sequences are 59 and 62% homologous to each other, respectively. The B. stearothermophilus protein differs most significantly from that of B. licheniformis in that it possesses a 32-res...
متن کاملKinetic study of the irreversible thermal denaturation of Bacillus licheniformis alpha-amylase.
The irreversible thermal inactivation of Bacillus licheniformis alpha-amylase was studied. A two-step behaviour in the irreversible denaturation process was found. Our experimental results are consistent only with the two-step model and rule out the two-isoenzyme one. They suggest that the deactivation mechanism involves the existence of a temperature-dependent intermediate form. Therefore the ...
متن کاملMutagenesis of Bacillus Licheniformis through Ethyl Methanesulfonate for Alpha Amylase Production
The present study is concerned with the improvement of Bacillus licheniformis strain GCB30 for alpha amylase production in 250 ml Erlenmeyer flasks. Chemical mutation using ethyl methanesulfonate (EMS 50-300 μ/ml) was undertaken for 10-60 min. Twenty eight isolates were selected on the basis of clear zones of starch hydrolysis. Only one isolate designated as B. licheniformis EMS-200 gave 102.78...
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ژورنال
عنوان ژورنال: Protein Engineering Design and Selection
سال: 1997
ISSN: 1741-0126,1741-0134
DOI: 10.1093/protein/10.5.541