EFFECTS OF BROMELAIN AND PRONASE ON ERYTHROCYTE-MEMBRANES

The effects of the proteolytic enzymes, bromelain and pronase, on mouse erythrocyte membranes have been examined using the techniques of polyacrylamide gel electrophoresis, surface labelling and crossed immunoelectrophoresis. The results show first that bromelain treatment digested protein bands, I, II and III of mouse erythrocyte membranes while pronase only digested band III. Secondly, both bromelain and pronase removed glycoprotein and protein components from the outer surface of mouse erythrocytes. Thirdly, at least one antigen found on the surface of bromelain-modified erythrocytes. is present within the membranes, but is not detectable on the surface of normal erythrocytes. On the basis of these results it is concluded that the proteases digest outer structures made up of protein and glycoprotein thereby exposing antigens that are normally hidden. It was observed that digestion, probably by endogenous proteases, persisted after bromelain and pronase-treated cells were washed. The possibility that this digestion may have contributed towards the revelation of target antigens was investigated. The inhibition of the persisting digestion did not reduce the number of antibody-producing cells detected. © 1979.