BIOCHEMICAL STUDIES OF MINERALIZED TISSUE PROTEOGLYCANS

最近，已经开始了几项研究，以调查 矿化组织的大分子，以阐明它们的作用 在生物钙化过程中。蛋白多糖(PG)是一种 骨和牙本质细胞外基质的非胶原性成分。 这项提案的目的是严格描述骨骼的PG。 并研究骨前列腺素的代谢特征，这可能是 与成矿有关的。骨质疏松症与骨质疏松症的特性比较 牙本质PG可以提供关于所需PG的特征的数据 用于正常的钙化。此外，各种细胞培养系统将被 建立并评价了它们作为PG研究模型的适用性 新陈代谢。 这些研究将使用广泛的预防措施，以避免人为因素 PGs的蛋白分解降解。此外，还提供了顺序提取过程 将使用提供两个PG池的PG：一个来自非矿化 一种来自基质，另一种来自组织钙化区域。PGS和组件 糖胺多聚糖(GAG)的化学特征是通过特定的 酶消化与各种层析和 离心法。骨前列腺素的代谢特征将是 通过结合使用特定的放射性标记技术和 上述提取和表征方法。细胞培养系统将 在脉冲和脉冲追逐实验中也使用无线电标记程序。 将使用各种代谢抑制剂和效应剂来评估 不同系统的生物合成特征。 这些实验提供的数据将被用来设计研究 探讨骨和牙本质PGs改变中的具体事件 从各种营养侮辱。例如，氟化物和维生素A是 两种可能对骨骼和牙齿产生不利影响的营养素 结构。

Recently, several studies have been initiated to investigate the nature of the macromolecules of mineralized tissues in order to elucidate their roles in biological calcification. Proteoglycans (PGs) are one of the noncollagenous components of the extra-cellular matrix of bone and dentin. The aims of this proposal are to rigorously characterize the PGs of bone and to investigate the metabolic features of bone PGs which might be relevant to mineralization. Comparison of the characteristics of bone and dentin PGs may provide data regarding the features of PGs that are required for normal calcification. Also, various cell culture systems will be established and evaluated for their suitability as models for studying PG metabolism. These studies will use extensive precautions to avoid artifactual proteolytic degradation of PGs. Also, a sequential extraction procedure will be used which provides two pools of PGs: one from nonmineralized matrix and another from calcified areas of the tissue. PGs and constituent glycosaminoglycans (GAGs) will be characterized chemically by specific enzyme digestion in conjunction with various chromatographic and centrifugation procedures. Metabolic characteristics of bone PGs will be studied by using a specific radiolabeling technique in conjunction with the extraction and characterization methods above. Cell culture systems will also use radiolabeling procedures in pulse and pulse-chase experiments. Various metabolic inhibitors and effectors will be used to assess the biosynthetic features of the different systems. The data provided by these experiments will be used in designing sutdies to probe specific events in the alteration of bone and dentin PGs resulting from various nutritional insults. For example, fluoride and vitamin A are two nutrients which can have adverse affects on skeletal and dental structure.