Purification and characterization of a prolidase from Lactobacillus casei subsp. casei IFPL 731

Abstract

A peptidase showing a high level of specificity towards dipeptides of the X-Pro type was purified to homogeneity from the cell extract of Lactobacillus casei subsp. casei IFPL 731. The enzyme was a monomer having a molecular mass of 41 kDa. The pH and temperature optima were 6.5 to 7.5 and 55 degrees C, respectively. Metal chelating agents completely inhibited enzyme activity, indicating that the prolidase was a metalloenzyme. The Michaelis constant (K(m)) and Vmax for several proline-containing dipeptides were determined.