EFFECT OF POTENTIAL BINDING-SITE OVERLAP TO BINDING OF CELLULASE TO CELLULOSE - A 2-DIMENSIONAL SIMULATION

A computer simulation model for the binding of ligands to a totally an isotropic surface (infinite two-dimensional square lattice) with overl apping binding sites has been developed. The validity of the simulatio n has been proven by comparison with cases where the correct results a re known. The simulation of kinetics shows that when the lattice is cl ose to saturation, the true equilibrium state is reached extremely slo wly due to a lot of rearranging of the ligands on the lattice. Based o n these findings, the terms 'apparent saturation' and 'apparent maximu m coverage' have been introduced and defined. The largest discrepancie s between 'apparent maximum coverage' and the theoretically predicted value were observed for ligands of large size and/or irregular shape. As an example, the model has been applied to describe the binding of c ellobiohydrolase-I core to Avicel. A formula for calculation of the in trinsic binding constant, maximal binding capacity and specific surfac e of cellulose from real binding data has been derived.