pH studies of alpha-chymotrypsin with l-tryptophan esters

Boron in Drug Discovery: Carboranes as Unique Pharmacophores in Biologically Active Compounds

“…Chymotrypsin is a well-characterized digestive proteolytic enzyme that catalyzes the hydrolysis of peptides at the carboxy end of Tyr, Trp, and Phe residues. The aromatic recognition site of the enzyme is a hydrophobic pocket bound by enzyme peptide bonds 190–191–192 and 215–216. , A synthetic peptide, N-Cbz-Ala-Ala-Car (Ki = 0.3 mM), containing the Phe derivative closo - L -carboranylalanine (Car) was shown to be a better inhibitor of chymotrypsin than was N-Cbz-Ala-Ala-Phe (Ki = 1 mM). The closo -carborane cage is accommodated in the binding pocket of the enzyme with deformation of the molecular surroundings of the cavity.…”