Kinetically controlled equilibria. The perturbation of hydrolysis equilibria in reactions catalyzed by alpha-chymotrypsin immobilized on charges supports

The hydrolysis and synthesis of N-Acetyl-I-tyrosine-ethyl-ester catalyzed by α-chymotrypsin immobilized in polymeric supports (Sephadex), with positive or negative stationary charges has been studied. Charged matrices perturbed the equilibrium (at pH 9.0), so that no complete hydrolysis was observed in the bulk solution and ester could be synthetized from acid and alcohol. The change is due to dipole orientation energies in the electric double layer where the reactions are catalyzed. This represents a situation where the equilibrium in the system is kinetically controlled by the equilibrium in a sub-system (here the electric double layer).