Scientist John Northrop crystallized chymotrypsin in the early
1930’s. In the following years, other scientists contributed to the
characterization of this enzyme, and now, it is one of the most well understood
Chymotrypsin is a digestive enzyme produced by the pancreas, and
it is responsible for the breakdown of proteins and polypeptides. Specifically,
it is an endopeptidase, and breaks bonds within a polypeptide. Without
chymotrypsin, proper food digestion cannot occur. Chymotrypsin consists of two
chains, and is made up of 245 amino acids (Figure 1).
An important component of
chymotrypsin is the catalytic triad. This triad is made up of residues Serine
195, Histidine 57, and Aspartate 102 (Figure 2). This triad is important for
chymotrypsin activity because the residues work to stabilize the enzyme and
promote catalysis. In the triad, the aspartate and histidine are bound to each
other by hydrogen bonds, allowing for serine to become a nucleophile to
catalyze the breakdown of proteins.