CONFORMATION OF DENTAL SALIVARY MOLECULES

该项目的长期目标是定义 唾液大分子的构象及其生物学意义 功能。最终，这些信息将被用于开发合成的 唾液用于唾液功能障碍患者。初步研究 将重点介绍以下两个腮腺唾液大分子：(1) 和(2)富含脯氨酸的糖蛋白“PRG”。生物学的 他汀类和PRG的功能包括调节 唾液和牙齿表面之间的钙磷平衡，而 PRG还参与咀嚼润滑，形成获得性 牙釉质膜和细菌从口腔清除。这个 研究方法将是圆二向色性(CD)和二维 H1-核磁共振(n.m.r)分光镜。这个特别的 方法学和唾液大分子的结合非常适合 因为：(1)存在这些分子的初级序列数据，并且 (2)它们足够小，可以进行严格的构象分析。这个 具体的研究方法将首先利用已定义的合成多肽 半经验预测的二级结构域类似物 计算。一旦建立了该二级结构的存在 利用CD光谱，n.m.r.分析将开始。使用n.m.r。 方法，得到大约一半的多肽键角。这个 剩余的多肽键角将由计算机分析确定。这 将对每个二级结构域重复该过程，直到 整个二级构象已被绘制出来。下一步是 他瑟林将从合成多肽模型发展到 天然的、完整的分子。斯塔瑟林将接受N.M.R.的检查。光谱学 和指定的三级结构。了解3维 他汀类药物和部分钙结合功能区的结构 在PRG中，然后进行钙滴定，并改变 构象将被阐明。基于这些结果，计算机分析 将被用来预测更有效的功能域是否可以 发展起来的。改良的钙结合和/或合成类似物 分别用于斯塔瑟林和PRG的润滑性功能区将 然后做好增强生物活性的准备和测试。

The long range goal of this project is to define the relationships between the conformation of salivary macromolecules and their biological functions. Ultimately, this information will be used to develop synthetic saliva for use in patients with salivary dysfunctions. Initial studies will focus on the following two parotid salivary macromolecules: (1) "statherin" and (2) the proline-rich glycoprotein, "PRG". The biological functions of statherin and PRG include the regulation of the calcium-phosphate equilibrium between saliva and the tooth's surface, while PRG also takes part in masticatory lubrication, the formation of acquired dental enamel pellicle and bacterial clearance from the oral cavity. The methods of study will be circular dichroism (CD) and 2-dimensional H1-nuclear magnetic resonance (n.m.r.) spectroscopies. This particular combination of methodologies and salivary macromolecules are well suited to each other since: (1) primary sequence data exists for these molecules and (2) they are small enough to undergo rigorous conformational analyses. The specific methods of study will first utilize defined synthetic polypeptide analogs of secondary structural domains as predicted by semi-empirical calculations. Once the presence of that secondary structure is established with CD spectroscopy, the n.m.r. analysis will begin. Using n.m.r. methods, roughly half of the peptide bond angles will be obtained. The remaining peptide bond angles will be specified by computer analysis. This procedure will be repeated for each secondary structural domain until the entire secondary conformation has been mapped out. The next step for statherin will be to proceed from the synthetic polypeptide models to the native, intact molecule. Statherin will be examined by n.m.r. spectroscopy and the tertiary structure specified. Knowing the 3-dimensional architecture of statherin and selected calcium-binding functional domains in PRG, calcium titrations will then be performed and changes in conformation will be elucidated. Based on these results, computer analysis will be used to predict if more effective functional domains can be developed. The improved synthetic analogs of the calcium-binding and/or lubricatory functional domains for statherin and PRG, respectively, will then be prepared and tested for enhanced biological activity.