fulltext.study @t Gmail

Alteration of Bacillus subtilis XynA endoxylanase substrate selectivity by site-directed mutagenesis

Paper ID Volume ID Publish Year Pages File Format Full-Text
17972 42708 2007 7 PDF Available
Title
Alteration of Bacillus subtilis XynA endoxylanase substrate selectivity by site-directed mutagenesis
Abstract

Bacillus subtilis endoxylanase XynA was engineered by site-directed mutagenesis to alter its substrate selectivity, i.e. the ratio of its capacity to solubilise water-unextractable arabinoxylans (WU-AX) to its capacity to hydrolyse water-extractable AX (WE-AX). Four surface exposed aromatic residues were targeted for mutation to alanine, either individually (Y113 and W185) or jointly (F48, Y94, Y113 and W185), based on the general role of aromatic residues in the binding of endoxylanases to insoluble substrates and the hypothesis that they affect the activity of endoxylanases towards WU-AX. Determination of the substrate selectivity factors and WU-AX degradation profile of the wild type and mutant enzymes using an elaborate procedure requiring incubation of native wheat flour WU-AX and WE-AX with different enzyme levels showed that mutants W185A and 4mutA, the mutant containing all four mutations, displayed lower selectivity towards WU-AX than the wild type recombinant endoxylanase. Each of the endoxylanases had similar binding activity to wheat flour WU-AX and insoluble oat spelt xylan.

Keywords
AX, arabinoxylan(s); A/X, arabinose to xylose ratio; GLC, gas liquid chromatography; GH, glycoside hydrolase; HPSEC, high performance size exclusion chromatography; MW, molecular weight(s); RX, reducing xylose ends; S-AX, solubilised arabinoxylan(s); SSF,
First Page Preview
Alteration of Bacillus subtilis XynA endoxylanase substrate selectivity by site-directed mutagenesis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Enzyme and Microbial Technology - Volume 41, Issues 1–2, 2 July 2007, Pages 85–91
Authors
, , , , , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us