Improving the catalytic performance of a GH11 xylanase by rational protein engineering.

摘要: XynCDBFV from Neocallimastix patriciarum is among the most effective xylanases and holds great potentials in a wide variety of industrial applications. In present study, several active site residues were modified referring to instrumental information complex structure xylooligosaccharides. Among 12 single mutants, W125F F163W show increased activity comparing wild-type protein. The double mutant W125F/F163W was then generated which displayed nearly 20 % increase enzyme activity. Although showed 5 °C reduction optimal temperature, it still preserves similar thermostability more than at temperatures lower 60 °C. These properties make suitable candidate for commercial applications that involve operating temperatures. Furthermore, we investigated effect N-glycosylation on when expressed yeast strain Pichia pastoris use. Two potential glycosylation sites (Asn-37 Asn-88) examined, their roles performance validated. We found N-glycosylations are related both catalytic heat stability, with Asn-37 motif playing dominant role. Collectively, enzymatic improved by molecular engineering, influences have been clearly elucidated herein.