Deacylation kinetics of gamma-chymotrypsin in solution and in the crystal.

The rate of catalyzed hydrolysis of the acyl enzyme analogs indolacryloyl-gamma-chymotrypsin and furylacryloyl-gamma-chymotrypsin in the crystal has been measured by single crystal microspectrophotometry and compared with the rate of catalyzed hydrolysis of acyl-gamma-chymotrypsin in solution and acyl-alpha-chymotrypsin both in solution and in the crystal. The maximal deacylation rate is the same for both species and independent of the physical state. However, the pH dependence of the deacylation rate of crystalline acyl-gamma-chymotrypsin shows a 0.9 unit shift in the pK of the catalytic system which is unique and probably consequent to specific lattice interactions.