NORMAL & PATHOLOGICAL ENAMEL MINERALIZATION

我们了解正常和病理性牙釉质的长期策略 矿化是确定：a）沉淀的驱动力， 磷酸钙盐，B）在釉质形成过程中的细胞作用， 建立这样的驱动力，以及c）可能的监管 与基质-矿物质相互作用有关的釉质发生机制。 所获得的信息将应用于病理学的研究。 用动物模型（小型猪和大鼠）在不同氟浓度下进行釉质形成 政权。 本建议包括以下几个具体方面： 从单个动物的分泌釉质中分离出液相 （小型猪），其离子组成的测定及其变化 由病理因素（氟化物）引起。 微体积分析 流体将通过使用离子色谱法和微- 个电极 2)液体中钙结合配体的鉴定。 流体中的蛋白质成分将通过微透析分离， 电泳和色谱法。 钙离子结合特性的研究 分离的流体成分将通过使用离子- 特异性电极、45 Ca放射自显影和流速透析。 基于 根据上述结果，我们将重新评估 釉质流体相对于釉质和其它磷酸钙， 兴趣 3)釉原蛋白和釉蛋白的性质研究 猪和小鼠模型，以及它们的原位降解。 的 有关的性质是：a）它们在磷灰石上的选择性吸附 表面，B）它们在生理水溶液中的溶解度，和c） 它们的疏水/亲水性质。 4)吸附机理 分泌的釉原蛋白附着在磷灰石表面。 选择性吸附 的釉原蛋白将与特定片段的存在， N-和C-末端，两者在基质中具有高度同源性 哺乳动物牙釉质的蛋白质。 还将努力查明 链段对溶液和固体中分子构象的影响 表面。 5)基质矿物功能方面的研究 釉质矿化中的相互作用。 兴趣将集中在 磷灰石晶体的蛋白质涂层对（a）掺入 离子（钙、磷酸盐和氟化物）从溶液中迁移到晶体上 表面，（B）在流体状环境中的沉淀动力学，和（c） 生长晶体的聚集和形态。

Our long-term strategy for understanding normal and pathological enamel mineralization is to determine: a) the driving force for precipitation of calcium phosphate salts during amelogenesis, b) the cellular role in establishing such a driving force, and c) the possible regulatory mechanism(s) of amelogenesis related to the matrix-mineral interaction. The information obtained will be applied to the study of pathological amelogenesis using animal models (minipigs and rats) under various fluoride regimes. The present proposal includes the following specific aspects: 1) Separation of the fluid phase from the secretory enamel of a single animal (minipig), determination of its ionic composition, and changes in it induced by pathological agents (fluoride). Analyses of micro volumes of the fluid will be conducted by the use of ion chromatography and micro- electrodes. 2) Identification of the calcium-binding ligands in the fluid. The protein constituents in the fluid will be separated by microdialysis, electrophoresis, and chromatography. The calcium-binding properties of the separated fluid constituents will be determined through the use of ion- specific electrodes, 45Ca autoradiography, and flow-rate dialysis. Based on the foregoing results, we will re-evaluate the degree of saturation of enamel fluid with respect to enamel and other calcium phosphates of interest. 3) Investigation of the properties of amelogenins and enamelins of porcine and murine models, and their degradation in situ. The properties concerned are: a) their selective adsorption onto apatitic surfaces, b) their solubility in physiologic aqueous solutions, and c) their hydrophobic/hydrophilic nature. 4) The mechanism of adsorption of the secreted amelogenin onto apatitic surfaces. The selective adsorption of the amelogenin will be related to the presence of specific segments at the N- and C-terminals, both of which have a high homology in the matrix proteins of mammal enamel. Efforts will also be made to ascertain the effect of segments on the molecular conformation in solutions and on solid surfaces. 5) Investigation of the functional aspects of the matrix-mineral interaction in enamel mineralization. Interest will be focused on the effects of protein coatings of apatite crystals on (a) the incorporation of ions (calcium, phosphate, and fluoride) from solutions onto the crystal surfaces, (b) kinetics of precipitation in fluid-like environments, and (c) the aggregation and morphology of growing crystals.