Chymotrypsinogen B2 (CTRB2)

Chymotrypsin is a digestive enzyme that can perform proteolysis. Chymotrypsin preferentially cleaves peptide amide bonds where the carboxyl side of amide bond (the S₁ position) is a tyrosine, tryptophan, or phenylalanine. These amino acids contain an aromatic ring in their sidechain that fits into a 'hydrophobic pocket' (the P₁ position) of the enzyme. The hydrophobic and shape complementarity between the peptide substrate S₁ sidechain and the enzyme P₁ binding cavity accounts for the substrate specificity of this enzyme. Chymotrypsin also hydrolyzes other amide bonds in peptides at slower rates, particularly those containing leucine at the S₁ position.Chymotrypsin is synthesized in the pancreas by protein biosynthesis as a precursor called chymotrypsinogen that is enzymatically inactive.