title: Engineering the hydrophobic residues of a GH11 xylanase impacts its adsorption onto lignin and its thermostability.
abstract: This study aimed to characterise the parameters governing the non-specific adsorption of a xylanase from Thermobacillus xylanilyticus (Tx-Xyn11) onto lignin isolated from maize stems. Such adsorption may be due to hydrophobic interactions between Tx-Xyn11 and lignin. Our strategy was to mutate hydrophobic residues present on the surface of Tx- Xyn11 into non-hydrophobic residues. Three mutants (P1, P2, and P3) with altered hydrophobic regions were produced and characterised. The thermostability of the P1 mutant was largely decreased compared with the thermostable Tx-Xyn11. The rate of adsorbed enzyme onto lignin was reduced to a similar extent for the P1 and P2 mutants, whereas the adsorption of the P3 mutant was less affected compared with that of Tx-Xyn11. When considered separately, the hydrophobic residues did not affect xylanase adsorption onto lignin. The addition of Tween 20 also led to the decreased adsorption of Tx-Xyn11 onto lignin. These results suggest that hydrophobic interactions are a key parameter in the interaction of Tx-Xyn11 with isolated lignin.
authors.affiliation: Université de Reims Champagne-Ardenne, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France; INRA, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France.
authors.forename: Harivony
authors.initials: H
authors.lastname: Rakotoarivonina
authors.affiliation: Université de Reims Champagne-Ardenne, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France; INRA, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Hermant
authors.affiliation: Université de Reims Champagne-Ardenne, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France; INRA, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Aubry
authors.affiliation: Université de Reims Champagne-Ardenne, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France; INRA, UMR614 Fractionnement des AgroRessources et Environnement, F-51100 Reims, France. Electronic address: caroline.remond@univ-reims.fr.
authors.forename: Caroline
authors.initials: C
authors.lastname: Rémond
mesh_terms: D000327:Adsorption; D056449:Bacillales / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D056804:Biofuels; D018533:Biomass; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D008031:Lignin / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D056804:Biofuels; D011994:Recombinant Proteins; D008031:Lignin; D043364:Endo-1,4-beta Xylanases
keywords: Adsorption; Bioethanol; Hydrophobic interactions; Hydrophobic residues; Lignin; Thermostability; Xylanase