BIOL 200 Lecture Notes - Lecture 6: Dna Replication, Post-Translational Modification, Hydrolase

Trypsin and chymotrypsin are members of the family of serine protease enzymes. They cleave peptide bonds at the C-terminal end of specific amino acid residues. Chymotrypsin recognizes aromatic residues such as phenylalanine, while trypsin recognizes lysine and arginine. The recognition of a particular side chain (side chain specificity) is fully determined by the structure and properties of the binding pocket. In the case of chymotrypsin the binding pocket is hydrophobic and is wide enough to accommodate an aromatic ring. Given what you know about the properties of Lys/Arg side chains, what can you say about the size/shape and possible interactions that would provide the substrate specificity in the case of trypsin? What amino acid residues would you expect to find in the active site of trypsin?