Rapid detection of Lys-gingipain using fluorogenic peptide substrate for diagnosis of periodontitis.

BACKGROUND/PURPOSE: Early detection of periodontitis and its associated pathogens has become imperative in oral health. (), a leading oral pathogen, is known to secrete Lys-gingipain (Kgp) enzyme. The aim of this study was to validate the detection of in human saliva samples by measuring the fluorescence intensity generated by a Lys-specific peptide substrate after it is cleaved in the presence of Kgp.

MATERIALS AND METHODS

To confirm the biological activity of the fluorogenic His-Glu-Lys containing peptide substrate which is specific to the Kgp, we compared the fluorescence intensity of the fluorogenic peptide substrate with saliva samples obtained from both healthy individuals (n = 31) and periodontitis patients (n = 30).

RESULTS

The results from the fluorogenic substrate were statistically compared with polymerase chain reaction (PCR) results of quantification. Whereas the PCR test had an area under curve (AUC) value of 0.729, the normalized relative fluorescence unit (RFU) obtained from fluorogenic peptide samples had an AUC value of 0.756.

CONCLUSION

We anticipate that the fluorogenic peptide substrate will assist in detecting early stages of periodontitis and ultimately prevent further complications. This fluorogenic peptide substrate can be used as a basic material for various types of biosensors.