Table 3.

Binding affinities and capacities of independent modules towards insoluble substrates as determined by binding isotherms*.

Protein	Biomass		Avicel		PASC
	Kd	Bmax	Kd	Bmax	Kd	Bmax
X2	12.12 ± 1.9	10.07 ± 0.25	24.15 ± 6.9	2.1 ± 0.22	9.96 ± 0.3	12.2 ± 0.3
CBM3	14.28 ± 3.5	5.15 ± 1.17	6.37 ± 0.07	10.6 ± 0.02	12.94 ± 1.15	6.68 ± 0.32
X2-CBM3	10.1 ± 1.15	13.02 ± 0.4	4.5 ± 0.53	12.17 ± 0.2	7.95 ± 0.3	11.57 ± 0.25
BSA	No binding		No binding		No binding

^*Values for K_d (µM) and B_max (µmol/g) were obtained from curve fitting using binding data presented in Fig. 5.