Purification and partial characterization of a dipeptidyl peptidase from Prevotella intermedia

A peptidase hydrolyzed X-Pro-p-nitroanilide was purified from the cell extract of Prevotella intermedia ATCC 25611 by ion-exchange chromatography and hydrophobic interaction chromatography. The purified enzyme exhibited a molecular size of 74 kDa from sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the maximum enzyme activity was found between pH 7.0 and pH 7.5. This peptidase was a serine enzyme and hydrolyzed Lys-Pro-p-nitroanilide, Arg-Pro-p-nitroanilide, and Ala-Pro-p-nitroanilide, but Lys-Ala-p-nitroanilide was not split. The enzyme may be classified as a dipeptidyl peptidase IV.