Directed Evolution of Thermus Maltogenic Amylase toward Enhanced Thermal Resistance

Directed evolution of Thermus maltogenic amylase toward enhanced thermal resistance.

The thermostability of maltogenic amylase from Thermus sp. strain IM6501 (ThMA) was improved greatly by random mutagenesis using DNA shuffling. Four rounds of DNA shuffling and subsequent recombination of the mutations produced the highly thermostable mutant enzyme ThMA-DM, which had a total of seven individual mutations. The seven amino acid substitutions in ThMA-DM were identified as R26Q, S1...

Modulation of substrate preference of thermus maltogenic amylase by mutation of the residues at the interface of a dimer.

To elucidate the relationship between the substrate size and geometric shape of the catalytic site of Thermus maltogenic amylase, Gly50, Asp109, and Val431, located at the interface of the dimer, were replaced with bulky amino acids. The k(cat)/K(m) value of the mutant for amylose increased significantly, whereas that for amylopectin decreased as compared to that of the wild-type enzyme. Thus, ...

Directed evolution of a bacterial α-amylase: Towards enhanced pH-performance and higher specific activity

Acarviosine-simmondsin, a novel compound obtained from acarviosine-glucose and simmondsin by Thermus maltogenic amylase and its in vivo effect on food intake and hyperglycemia.

Simmondsin was modified with acarviosine-glucose using the transglycosylation activity of Thermus maltogenic amylase to synthesize a novel compound with both antiobesity and hypoglycemic activity. The LC/MS and 13C NMR analyses confirmed that the structure of the major transglycosylation product was acarviosine-simmondsin (Acv-simmondsin), in which acarviosine was attached to the glucose moiety...

Enzymatic synthesis of glycosylated puerarin using maltogenic amylase from Bacillus stearothermophilus expressed in Bacillus subtilis.

BACKGROUND The maltogenic amylase from Bacillus stearothermophilus (BSMA) is a valuable biocatalyst that has been used to transglycosylate natural glycosides to improve solubility. To ensure safety, BSMA was produced in Bacillus subtilis, using new shuttle vector-based expression vectors. The transglycosylation of puerarin was also conducted with crude BSMA and analyzed. RESULTS Two expressio...