Quantitative approaches to the analysis of carbohydrate-binding module function

Carbohydrate-binding modules (CBMs) are important components of carbohydrate-active enzymes. Their primary functions are to assist in substrate turnover by targeting appended catalytic modules to substrate and concentrating appended catalytic modules on the surface of substrate. Presented here are four well-established methodologies for investigating and quantifying the CBM-polysaccharide binding relationship. These methods include: (1) the solid state depletion assay, (2) affinity gel electrophoresis, (3) UV difference and fluorescence spectroscopy, and (4) isothermal titration calorimetry. In addition, entropy-driven CBM-crystalline cellulose binding events and differential approaches to calculating stoichiometry with polyvalent polysaccharide ligands are also discussed.