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標題: Gene cloning, expression, and biochemical characterization of a recombinant trehalose synthase from Picrophilus torridus in Escherichia coli
作者: Chen, Y.S.
Lee, G.C.
Shaw, J.F.
關鍵字: high performance liquid chromatography;maltose;Picrophilus torridus;trehalose;trehalose synthase;enzyme;purification;maltose;identification;caldophilus;phosphate;envelope;sequence;stress;genome
Project: Journal of Agricultural and Food Chemistry
期刊/報告no:: Journal of Agricultural and Food Chemistry, Volume 54, Issue 19, Page(s) 7098-7104.
A trehalose synthase (TSase) gene from a hyperacidophilic, thermophilic archaea, Picrophilus torridus, was synthesized using overlap extension PCR and transformed into Escherichia coli for expression. The purified recombinant P. torridus TSase (PTTS) showed an optimum pH and temperature of 6.0 and 45 degrees C, respectively, and the enzyme maintained high activity at pH 5.0 and 60 degrees C. Kinetic analysis showed that the enzyme has a 2.5-fold higher catalytic efficiency (k(cat)/K-M) for maltose than for trehalose, indicating maltose as the preferred substrate. The maximum conversion rate of maltose into trehalose by the enzyme was independent of the substrate concentration, tended to increase at lower temperatures, and reached approximate to 71% at 20 degrees C. Enzyme activity was inhibited by Hg2+, Al3+, and SDS. Five amino acid residues that are important for alpha-amylase family enzyme catalysis were shown to be conserved in PTTS (Asp(203), Glu(245), Asp(311), His(106), and His(310)) and required for its activity, suggesting this enzyme might employ a similar hydrolysis mechanism.
ISSN: 0021-8561
DOI: 10.1021/jf060828q
Appears in Collections:食品暨應用生物科技學系

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