Proteins of the periodontium. Characterization of the insoluble collagens of bovine dental cementum.

Cyanogen bromide (CNBr) peptides were prepared of the insoluble collagen of bovine dental cementum. Following chromatographic separation, the peptides were identified by their amino-acid composition. Type I collagen ([alpha1(I)]2alpha2) accounted for more than 90% of the organic matrix, while Type III collagen ([alpha1(III)]3) was present at a level of approximately 5%. Amino-acid analyses revealed that the CNBr peptides from alpha1(I) and alpha2 chains of cementum closely resembled the corresponding peptides from calf skin. The only systematic difference was a higher level of hydroxylation of prolyl and lysyl residues of the cementum peptides.