Binding capacities for Thermomonospora fusca E3, E4 and E5, the E3 binding domain, and Trichoderma reesei CBHI on Avicel and bacterial microcrystalline cellulose

Equilibrium binding of Thermomonospora fusca E3, E4 and E5, the E3 binding domain (CBDE3), and Trichoderma reesei CBHI on Avicel PH102 and bacterial microcrystalline cellulose (BMCC) was studied. The maximum adsorption levels, Eb,m, for all four cellulases and the binding domain were 9–30 times higher on BMCC than on Avicel. The association constants for the individual cellulases were dependent upon the substrate; however, no obvious patterns were noted. A comparison of the T. fusca Ebms showed a decreasing power function relationship between molecular weight and maximum adsorption levels. This was particularly true for the cellulases binding on Avicel. The T. fusca binding results strongly suggest that binding capacity is a function of the cellulase size and the pore structure of the cellulose.