BIOCHEMISTRY AND MINERALIZATION OF TOOTH CEMENTUM

这些研究的目的是为了对 细胞外基质成分的结构和组织 牛牙骨质及其在矿化中的潜在作用(S)。这个 最丰富的有机成分的详细结构，类型I 胶原蛋白，将通过量化分子分布来研究 分子间的共价交联物及其前体醛 胶原蛋白纤维。这将通过对这些数据的量化分析来实现 化合物及其在原纤维中分子位置的测定 从NaB3H4还原的组织中分离这些多肽。基于 数据，我们可以获得有关特定三维的信息 牙骨质中胶原纤维的结构 组织的稳定性，并在组织的 矿化作用。这些数据将与牙本质和 从相同的牙齿和颌骨获得的牙槽骨。我们还将隔离 并研究这个组织的主要磷蛋白的结构， 潜在的矿化成核剂，也存在于EDTA中 作为不能溶解的分数。后一组分中的磷蛋白是 与矿物质和不溶的胶原蛋白纤维密切相关。这个 新发现的磷蛋白相关基因的分子起源 双功能交联物，组氨酸丙氨酸和赖氨酸丙氨酸及其 在分子组织中的功能意义将由 交联肽的分离及分子定位 这些多肽中的化合物。此外，主要的蛋白多糖， 另一种阴离子成分，将被分离并用琼脂糖凝胶分析- 并进行了详细的聚丙烯酰胺凝胶电泳法 用一大组单抗进行生化/免疫化学分析 针对结缔组织上存在的表位的抗体 蛋白多糖。 免疫组织化学技术也将被用于检查它们的组织 胶原蛋白的分布及其与胶原纤维的潜在相互作用 与胶结成矿有关的网络。最后，归纳 这些阴离子诱导的矿物的速率、生长速率和定位 牙骨质中的蛋白质(磷蛋白和蛋白多糖)固定在 不溶性胶原纤维将在透射电子显微镜水平上进行研究和比较。这 研究类型将提供有关这些项目参与情况的信息 矿化过程中的大分子及其与胶原的相互作用 进程。

These studies are directed towards obtaining a basic understanding of the structure and organization of the extracellular matrix components of the bovine tooth cementum and their potential role(s) in mineralization. The detailed structure of the most abundant organic component, type I collagen, will be studied by quantifying the molecular distribution of the covalent intermolecular cross-links and their precursor aldehydes in the collagen fibrils. This will be performed by quantitative analysis of these compounds and determination of their molecular loci within the fibril by isolating these peptides from the NaB3H4-reduced tissue. Based on the data, we can obtain information concerning the specific three-dimensional structure of collagen fibrils of cementum which is essential for stabilization of the tissue and plays an important role in the tissue's mineralization. These data will be compared with those of dentin and alveolar bone obtained from the same teeth and jaws. We will also isolate and study the structure of the major phosphoproteins of this tissue, potential nucleators for mineralization, present in EDTA-soluble as well as insoluble fractions. The phosphoproteins in the latter fraction are strongly associated with mineral and insoluble collagen fibrils. The molecular origin of the newly described phosphoprotein-associated bifunctional cross-links, histidinoalanine and lysinoalanine, and their functional significance in molecular organization will be pursued by isolating the cross-linked peptides and identifying the molecular loci of these compounds within the peptides. In addition, the major proteoglycans, another anionic component, will be isolated and analyzed by agarose- polyacrylamide gel electrophoresis and subjected to detailed biochemical/immunochemical analysis with the large panel of monoclonal antibodies directed against epitopes present on connective tissue proteoglycans. Immunohistochemical techniques will also be used to examine their tissue distribution and their potential interaction with collagen fibrillar network in relation to mineralization of cementum. Finally, the induction rates, growth rates and localization of mineral induced by those anionic proteins in cementum (phosphoproteins and proteoglycans) immobilized on insoluble collagen fibrils will be studied and compared on TEM level. This type of study will provide information concerning the involvement of these macromolecules and their interactions with collagen in the mineralization process.