Catalytic and adhesin activities of proteases: Porphyromonas gingivalis

Porphyromonas gingivalis, an anaerobic bacterium, is a contributing agent of periodontal (gum) disease. This disease is the primary cause of tooth loss in the Western world and is also associated with heart disease and other systemic diseases.

The bacterium secretes potent cysteine proteases called gingipains. These proteases are vital for the virulence of the bacterium. The proteases consist of a catalytic sub-unit and several other protein sub- units referred to as adhesins.

The adhesins bind to other bacteria, a process which is vital for colonisation of the oral cavity and also bind to host cells and proteins. It's most likely that the adhesin and protease activities of this protease are vital to the virulence of P. gingivalis.

Our research seeks to understand the determinants of both binding and protease specificity and we are using combinatorial peptide libraries to investigate.