Fig. 2

The affinity of recombinant CBMs for a soluble polysaccharides and b insoluble substrates. Figure 2a shows the non-denaturing PAGE that is carried out in a gel containing arabinoxylan (AX), glucuronoxylan (GX), carboxymethyl xylan (CMX), arabinan or arabinogalactan (AG). The control group contains no polysaccharide. The band of CBM would lag behind that of the control group if the CBM could bind to the corresponding polysaccharide. The numbers indicate the relative mobility rates of CBMs, which are negatively correlated with the affinity of CBMs for polysaccharides. Figure 2b shows the binding abilities of CBMs to microcrystalline cellulose, insoluble corncob xylan, delignified corncob and delignified Carolina poplar. The concentration of the protein solution without any substrate is defined as 100%