Crystal Structures of Five Bovine Chymotrypsin Complexes with P1 BPTI Variants

The bovine chymotrypsin–bovine pancreatic trypsin inhibitor (BPTI) interaction belongs to extensively studied models of protein–protein recognition. The accommodation of the inhibitor P1 residue in the S1 binding site of the enzyme forms the hot spot of this interaction. Mutations introduced at the P1 position of BPTI result in a more than five orders of magnitude difference of the association constant values with the protease. To elucidate the...