Chymotrypsin catalyzes the hydrolysis of a peptide bond. Two parts of chymotrypsin are of interest: the catalytic triad composed of residues His-57, Asp-102, Ser-195, and the oxyanion hole composed of Gly-193, Asp-194, Ser-195.
For a detailed examination of the hydrolysis mechanism, see: Stewart, J. J. (2017). An investigation into the applicability of the semiempirical method PM7 for modeling the catalytic mechanism in the enzyme chymotrypsin. Journal of Molecular Modeling, 23(5), 154, at https://link.springer.com/article/10.1007/s00894-017-3326-8
Files used in making this examination can be downloaded from http://openmopac.net/Manual/J_Mol_Mod_(2017)_files_Chymotrypsin_catalytic_mechanism/Supplementary_Material.html