Crystal structure of the Michaelis complex of trypsin with N-α-benzoyl-l-arginine ethyl ester

Abstract

The crystal structure of Michaelis complex of the bovine trypsin with N-α-benzoyl-l-arginine ethyl ester (BAEE) was determined at 2.30 Å resolution. The structure of enzyme-substrate complex was solved in space group H3₂. The active site of trypsin was found to be occupied with the N-α-benzoyl-l-arginine ethyl ester. The hydrolyzed product of substrate molecules was also crystallized with trypsin. The substrate was embedded within the S1 binding site of the enzyme, and showed contacts with Gly-195, Ser-216, and Ser-192. Some water molecules were also found within the vicinity of catalytic residues of enzyme. Interestingly, the hydrolyzed product present within the crystal lattice was found to be with inverted configuration. The crystal structure of trypsin in-complex with N-α-benzoyl-l-arginine ethyl ester has never been reported previously.