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ABSTRACT: Recombinant expression of the dextransucrase dsrS gene by Escherichia coli was optimized to produce 5850 U L(-1) (culture) of DSR-S, corresponding to a 30-fold increase compared with previous studies. Rational deletions of the signal peptide, the beginning of the variable region and the last four repeats of the C-terminal end caused no loss of activity. This new variant successfully purified was remarkably stable. With a k(cat) of 584 s(-1), it is the most efficient recombinant glucansucrase described to date. The synthesized polymer possesses more than 95% of alpha-1,6 links, like the dextran produced by the native enzyme, and innovative gel properties were obtained.
FEMS Microbiology Letters 09/2006; 261(2):203-10. · 2.05 Impact Factor