Probing enzyme stereospecificity. Inhibition of α-chymotrypsin and subtilisin Carlsberg by chiral amine- and aminoalcohol-derivatives

Abstract

Various enantiomeric amine and aminoalcohol amide and α-ketoamide derivatives have been evaluated as competitive inhibitors of the representative serine proteases α-chymotrypsin (CT) and subtilisin Carlsberg (SC). Each compound studied was an effective competitive inhibitor of both enzymes. However, only for the best inhibitor, N-pyruvoyl-1-(1-naphthyl)ethylamine (K1 27 μM for the S-enantiomer with CT), was noteworthy enantiomeric discrimination manifest, with the S-enantiomer being a significantly more powerful inhibitor of CT and SC than its R-counterpart by factors of 12.6- and 73-fold, respectively. The enzyme-inhibitor interactions responsible for this strong binding and enantiomeric discrimination were revealed by molecular modelling analyses.