Acid-soluble proteins of normal, regenerated, and periodontally diseased gingivae.

Abstract

The purpose of the study was to characterize the noncollagenous acid‐soluble proteins of gingiva and to determine their function. Gingival tissues of healthy adult dogs and those with spontaneously occurring advanced periodontitis were studied. The dental laminac from newborn puppies and skin of newborn and adult animals were also analyzed. Tissues were extracted with buffered salt at neutral pH followed by 0.5 M acetic acid. SDS‐polyacrylamide gel electrophoresis revealed that salt extracts of all of the tissues contained collagens and several more rapidly migrating components; the latter cross‐reacted with an antiserum to whole dog serum and were, therefore, derived from serum and tissue fluids. The acid extracts of normal gingiva contained a family of collagenase‐resistant, pepsin‐sensitive components ranging in size from about 32 kD to 75 kD. These components did not cross‐react with the antiserum and appeared to be components of the connective tissues. They were partially purified by DEAE‐cellulose chromarography and shown to be similar to the acidic structural glycoproteins of other connective tissues. These acid‐soluble proteins were present in moderate to large amounts in extracts of healthy gingival tissues and in trace amounts in dental lamina. The amount in extracts of regenerated gingiva was much greater than in extracts of normal gingiva. Only traces were found in the extracts of gingivae from animals with spontaneous periodontitis. The data indicate that these proteins may be important structural components of the normal connective tissue matrix, and their loss during the early stages of periodontitis may be an important event in progressive tissue destruction.