title: Synergistic cellulose hydrolysis can be described in terms of fractal-like kinetics.
abstract: A fractal-like kinetics model was used to describe the synergistic hydrolysis of bacterial cellulose by Trichoderma reesei cellulases. The synergistic action of intact cellobiohydrolase Cel7A and endoglucanase Cel5A at low enzyme-to-substrate ratios showed an apparent substrate inhibition consistent with a case where two-dimensional (2-D) surface diffusion of the cellobiohydrolase is rate-limiting. The action of Cel7A core and Cel5A was instead consistent with a three-dimensional (3-D) diffusion-based mode of action. The synergistic action of intact Cel7A was far superior to that of the core at a high enzyme-to-substrate ratio, but this effect was gradually reduced at lower enzyme-to-substrate ratios. The apparent fractal kinetics exponent h obtained by nonlinear fit of hydrolysis data to the fractal-like kinetics analogue of a first-order reaction was a useful empirical parameter for assessing the rate retardation and its dependence on the reaction conditions.
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Vanemuise 46-138, Tartu 51010, Estonia.
authors.forename: Priit
authors.initials: P
authors.lastname: Väljamäe
authors.forename: Kalle
authors.initials: K
authors.lastname: Kipper
authors.forename: Göran
authors.initials: G
authors.lastname: Pettersson
authors.forename: Gunnar
authors.initials: G
authors.lastname: Johansson
mesh_terms: D002475:Cellobiose / Q000032:analysis / Q000378:metabolism; D002480:Cellulase / Q000302:isolation & purification / Q000378:metabolism*; D002482:Cellulose / Q000302:isolation & purification / Q000378:metabolism*; D043366:Cellulose 1,4-beta-Cellobiosidase / Q000302:isolation & purification / Q000378:metabolism*; D004058:Diffusion; D017709:Fractals; D041822:Gluconacetobacter xylinus / Q000737:chemistry; D006868:Hydrolysis; D007700:Kinetics; D017711:Nonlinear Dynamics; D014242:Trichoderma / Q000201:enzymology
chemical_list: D002475:Cellobiose; D002482:Cellulose; C407024:endoglucanase Cel5A; D002480:Cellulase; D043366:Cellulose 1,4-beta-Cellobiosidase