Purification and partial characterization of a lysine-specific protease of Porphyromonas gingivalis

A lysine-specific protease hydrolysing peptide bonds at the carboxyl side of lysine residues in Porphyromonas gingivalis was purified from culture supernatant by a combination of ion-exchange chromatography, gel filtration, and affinity chromatography. The molecular mass was 48 kDa and the pI value was 7.3. The enzyme hydrolysed the peptide bonds at the carboxyl side of lysine residues in synthetic substrates and natural proteins.