PRP's act as highly potent inhibitors of crystal growth of calcium phosphates. They provide a protective and reparative environment for dental enamel which is important for the integrity of the teeth.
Proteolytically cleaved; PRP-2, PRP-1, PIF-S and Db-S yield PRP-4, PRP-3 (protein A), PIF-F and Db-F, respectively. An hexuronic acid was shown to be linked to Ser-33 in about 40% of the polypeptides. Neither the structure of the carbohydrate (whether glucuronic acid or an isomer of), nor the linkage (whether a glycoside or an ester) has been definitely established.