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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
22
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pubmed:dateCreated |
2005-11-10
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pubmed:abstractText |
Wheat endoxylanase inhibitor TAXI-I inhibits microbial glycoside hydrolase family 11 endoxylanases. Crystallographic data of an Aspergillus niger endoxylanase-TAXI-I complex showed His374 of TAXI-I to be a key residue in endoxylanase inhibition. Its role in enzyme-inhibitor interaction was further investigated by site-directed mutagenesis of His374 into alanine, glutamine or lysine. Binding kinetics and affinities of the molecular interactions between A. niger, Bacillus subtilis, Trichoderma longibrachiatumendoxylanases and wild-type TAXI-I and TAXI-I His374 mutants were determined by surface plasmon resonance analysis. Enzyme-inhibitor binding was in accordance with a simple 1 : 1 binding model. Association and dissociation rate constants of wild-type TAXI-I towards the endoxylanases were in the range between 1.96 and 36.1 x 10(4)m(-1) x s(-1) and 0.72-3.60 x 10(-4) x s(-1), respectively, resulting in equilibrium dissociation constants in the low nanomolar range. Mutation of TAXI-I His374 to a variable degree reduced the inhibition capacity of the inhibitor mainly due to higher complex dissociation rate constants (three- to 80-fold increase). The association rate constants were affected to a smaller extent (up to eightfold decrease). Substitution of TAXI-I His374 therefore strongly affects the affinity of the inhibitor for the enzymes. In addition, the results show that His374 plays a critical role in the stabilization of the endoxylanase-TAXI-I complex rather than in the docking of inhibitor onto enzyme.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
1742-464X
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pubmed:author |
pubmed-author:BrijsKristofK,
pubmed-author:CampenhoutStevenS,
pubmed-author:CourtinChristophe MCM,
pubmed-author:De RanterCamiel JCJ,
pubmed-author:DeclerckPaul JPJ,
pubmed-author:DelcourJan AJA,
pubmed-author:FierensKatleenK,
pubmed-author:GebruersKurtK,
pubmed-author:GilsAnnA,
pubmed-author:RabijnsAnjaA,
pubmed-author:RobbenJohanJ,
pubmed-author:SansenStefaanS,
pubmed-author:VolckaertGuidoG
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pubmed:issnType |
Print
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pubmed:volume |
272
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
5872-82
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:16279951-Alanine,
pubmed-meshheading:16279951-Amino Acid Substitution,
pubmed-meshheading:16279951-Aspergillus niger,
pubmed-meshheading:16279951-Bacillus subtilis,
pubmed-meshheading:16279951-Circular Dichroism,
pubmed-meshheading:16279951-Endo-1,4-beta Xylanases,
pubmed-meshheading:16279951-Glutamine,
pubmed-meshheading:16279951-Histidine,
pubmed-meshheading:16279951-Hydrogen Bonding,
pubmed-meshheading:16279951-Hydrogen-Ion Concentration,
pubmed-meshheading:16279951-Isoelectric Focusing,
pubmed-meshheading:16279951-Kinetics,
pubmed-meshheading:16279951-Lysine,
pubmed-meshheading:16279951-Models, Molecular,
pubmed-meshheading:16279951-Mutagenesis, Site-Directed,
pubmed-meshheading:16279951-Pichia,
pubmed-meshheading:16279951-Plant Proteins,
pubmed-meshheading:16279951-Protein Binding,
pubmed-meshheading:16279951-Recombinant Proteins,
pubmed-meshheading:16279951-Surface Plasmon Resonance,
pubmed-meshheading:16279951-Trichoderma,
pubmed-meshheading:16279951-Triticum
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pubmed:year |
2005
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pubmed:articleTitle |
His374 of wheat endoxylanase inhibitor TAXI-I stabilizes complex formation with glycoside hydrolase family 11 endoxylanases.
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pubmed:affiliation |
Katholieke Universiteit Leuven, Laboratory of Food Chemistry, Leuven, Belgium. katleen.fierens@biw.kuleuven.be
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
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