title: Model cellulose films exposed to H. insolens glucoside hydrolase family 45 endo-cellulase--the effect of the carbohydrate-binding module.
abstract: The effects of enzyme structure and activity on the degradation of model cellulose substrates were investigated by ellipsometry for the cellulase Humicola insolens GH45. The inactive variant D10N was found to adsorb at the cellulose surface but also to be incorporated into the cellulose films to an extent that depended on pH. For the native protein, the initial adsorption monitored for the inactive variant D10N was followed by enzyme-mediated degradation of the cellulose films. Again, a dependence on pH was found, such that higher pH resulted in slower enzymatic degradation. Removing the carbohydrate-binding module eliminated this pH dependence but also resulted in a decreased adsorption to the cellulose surface, and in a decreased net catalytic effect.
authors.affiliation: Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm, Sweden. jonny.olaspers@bredband.net
authors.forename: Jonny
authors.initials: J
authors.lastname: Eriksson
authors.forename: Martin
authors.initials: M
authors.lastname: Malmsten
authors.forename: Fredrik
authors.initials: F
authors.lastname: Tiberg
authors.forename: Thomas Hønger
authors.initials: TH
authors.lastname: Callisen
authors.forename: Ture
authors.initials: T
authors.lastname: Damhus
authors.forename: Katja S
authors.initials: KS
authors.lastname: Johansen
mesh_terms: D001203:Ascomycota / Q000201:enzymology*; D002480:Cellulase / Q000378:metabolism*; D002482:Cellulose; D005656:Fungal Proteins / Q000378:metabolism; D005959:Glucosidases / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D011487:Protein Conformation
chemical_list: D005656:Fungal Proteins; D002482:Cellulose; D005959:Glucosidases; D002480:Cellulase