MINERAL INDUCTION BY IMMOBILIZED DENTIN PHOSPHOPROTEIN

这项研究的长期目标是深入了解 通过测定矿化容量探讨生物矿化机理 分离的基质蛋白来诱导和促进矿物质 队形。拟议研究的目的是进行 牙本质矿化潜能的初步研究 使用体外模型系统的磷蛋白。在这个系统中 牙本质磷蛋白将通过共价连接固定化 一种模型底物，聚丙烯酰胺，以模拟其与 牙本质的胶原网。被灌输的人的能力 从亚稳态诱导矿物形成的磷蛋白 不会自发沉淀的溶液 保持恒定的钙和磷活性， 与体液的相似程度，将会被确定。这个 还将在溶液中加入磷酸蛋白，以确定 游离蛋白质对矿物质形成和生长的影响 由固定化蛋白诱导。 钙和磷的浓度和pH值将保持不变 常量与恒化器一起使用，该恒化器可以感知 孵化解决方案，并通过添加 离子。原子光谱学和比色法将用于 确定孵化液保持在辅助剂状态 组成。诱导矿物质的能力将被确定。 就第一种矿物形成和形成之前的时间延迟而言 矿物形成的速度。形成的矿物类型将是 用X射线衍射法和红外分光光度法进行了测定。 在这项拟议的调查中获得的结果将有助于 对矿物质的正常作用机制的理解 在钙化组织中诱导。结果也将会有 在病理性疾病中的含义是正常的 没有矿化模式，例如某些类型的矿化 牙本质磷蛋白似乎是牙本质发育不完全的原因 缺席。

The long-term objective of this research is to gain insights into the mechanisms of biomineralization by determining the capacities of isolated matrix proteins to induce and to promote mineral formation. The purpose of the proposed research is to conduct pilot studies on the mineralization potential of dentin phosphoprotein using an in vitro model system. In this sytem dentin phosphoprotein will be immobilized by covalent linkage to a model substrate, polyacrylamide, to simulate its attachment to the collagen network of dentin. The capacity of the immbolized phosphoprotein to induce mineral formation from metastable solutions which do not spontaneously precipitate and that maintained at constant calcium ad phosphate activities, approximating those of body fluids, will be determined. The phosphoprotein also will be added, in solution, to determine the effects the free protein on the formation and growth of mineral induced by the immobilized protein. The calcium and phosphate concentrations and pH will be held constant with a chemostat that senses minute changes in the incubation solution and corrects for these changes by addition of the ions. Atomic spectroscopy and colorimetry will be used to ascertain that the incubation solution is maintained at cosntant composition. The capacity to induce mineral will be determined in terms of the time lag until the first mineral is formed and the rate of mineral formation. The type of mineral formed will be determined by X-ray diffraction and infrared spectrophotometry. The results obtained in this proposed investigation will contribute to an understanding of the normal mechanisms of mineral induction in calcified tissues. The results will also have implications in the pathological disorders in which the normal mineralization patterns are absent, such as some types of dentiogenesis imperfecta whee the dentin phosphoprotein seems to be absent.