Identification of laminin receptor in gingival tissue and its interaction with tooth cementum laminin.

1. A gingival epithelial cell surface receptor for laminin was isolated from bovine gingival tissue by affinity chromatography on laminin. 2. The protein bound by the affinity matrix from octylglucoside extracts of gingival membrane preparation eluted from the column with the cation-free buffer containing EDTA, and exhibited a mol. wt of 67 kDa. 3. The 67 kDa protein following radioiodination was incorporated into liposomes, which showed a specific affinity towards laminin-coated surfaces, as well as to the tooth cementum. 4. The results provide for the first time evidence for the existence of a gingival cell surface laminin receptor, and indicate that the maintenance of the cemento-epithelial junction involves the interaction between the cementum laminin and its receptor on gingival epithelium.