A synergistic kinetics model for enzymatic cellulose hydrolysis compared to degree-of-synergism experimental results.

It is demonstrated that a two-enzyme component synergistic model can account for the observation that the degree of synergism goes through a maximum as the total enzyme concentration is increased. The degree of synergism is low at low enzyme concentration because the extent of conversion is low and therefore the cellulose chain ends, present originally, are not exhausted; thus the action of the cellobiohydrolase (CBH) is not dependent on the chain ends generated by the endoglucanase (EG). The degree of synergism declines at high enzyme concentration due to saturation of adsorption sites with CBH, thus decreasing the generation of chain ends by EG.