Whole Saliva Proteases: Development of Methods for Determination of Origins

Abstract

Whole saliva contains several proteases not found in the major gland secretions (1–5). Although many oral microorganisms with protease activity have been reported (6–16), none has been shown to provide the origin for any oral protease. Our interest has been the origin (host/microbe) of proteases in the oral cavity of man. In order to begin such a study, we sought a protease assay which would yield information pertinent to the recognition and characterization of proteases without the requirement for extensive purification efforts. We chose to use protein substrate cleavage patterns as visualized by Polyacrylamide „gel electrophoresis (PAGE) as a method of protease assay, recognition, and characterization. Thus, determination of the cleavage patterns generated from a collection of substrate proteins by saliva, for example, will provide a basis for the recognition of similar proteolytic activities which might be produced by oral microorganisms. In addition, extremely limited proteolysis (one scission per substrate molecule), which would be undetected with most other assay techniques, may be detected by PAGE analyses. In this report our initial results using radio-acetylated bovine serum albumin (BSA) as a substrate protein are presented.