TERTIARY STRUCTURES OF SALIVARY PROTEINS

腮腺、颌下腺和舌下腺的分泌物含有 大量的蛋白质蛋白质，并可选择性地吸附到 牙釉质的羟基磷灰石状表面。一旦被吸附到 牙齿表面，这些蛋白质可能参与了 牙齿表面的脱矿/再矿化。此外，这些 蛋白质可能表现出在早期很重要的受体样结构域。 可能参与的特定口腔微生物的定植 龋齿和/或牙周病。有重要证据表明 提示某些唾液蛋白的受体样域不是 细菌可接触到的，除非唾液蛋白被吸附到固体上 相，如羟基磷灰石。证据主要来自于 生化和显微技术表明构象 细菌结合部位周围发生变化。然而，这些技术是 受限于它们的低分辨率。一种新的战略，用来 研究其他蛋白质复合体的构象变化 纳入本建议书，以确定 构象变化，可能分解为特定的氨基酸 残留物。 这项建议的具体目的是： 进行氨基酸侧链的共价蛋白质修饰 他汀类药物和/或组蛋白5，并测定氨基酸的变化 溶液标记蛋白质与标记蛋白质的反应性 在羟基磷灰石上吸附之后。在单独的实验中， 赖氨酸、酪氨酸、谷氨酰胺和组氨酸特异性试剂将 添加到蛋白质样本中。使用氨基酸分析的组合，氨基酸 酸测序和液体闪烁计数，范围和 将确定修饰氨基酸的位置。 这一目标的成功实现将为更多的 使用酸性富含脯氨酸的蛋白质的扩展研究，只有在被吸附时 在羟基磷灰石上，已被证明结合粘性放线菌， 牙龈类杆菌和变形链球菌。这个项目的第一阶段 项目在发展小型实验方法中具有重要意义 蛋白质，即STATHIN5和组蛋白5，在其普遍应用于 更大的酸性富含脯氨酸的蛋白质。某些口腔微生物 也以依赖于吸附的方式与施他林结合，因此施他林将 在方法开发中发挥有益的作用。组蛋白5将用于 他汀类药物不含组氨酸的研究进展 任何组氨酸残留物。该项目的最终目标将是 确定哪些氨基酸参与蛋白质与细菌的相互作用。

Secretions from the parotid, submandibular and sublingual glands contain a significant amount of protein proteins and may be selectively adsorbed onto the hydroxyapatite-like surface of dental enamel. Once adsorbed onto the tooth surface, these proteins may be involved in the demineralization/remineralization of the tooth surface. In addition, these proteins may exhibit receptor-like domains which are important In the early colonization of specific oral microorganisms which may be involved in caries and/or periodontal disease. There is significant evidence that suggests that the receptor-like domain for certain salivary proteins is not accessible to bacteria unless the salivary protein is adsorbed onto a solid phase such as hydroxyapatite. The evidence has largely been derived from biochemical and microscopic techniques which suggest that the conformation around the bacterial binding site changes. These techniques, however, are limited by their low degrees of resolution. A new strategy, employed to study conformational changes in other protein complexes has been incorporated into this proposal in order to determine the location of conformational changes, with possible resolution to the specific amino acid residue. The specific aim of this proposal is: To perform covalent protein modification of amino acid side chains of statherin and/or histatin 5 and to determine changes in amino acid reactivity between protein labeled in solution and protein labeled following adsorption onto hydroxyapatite. In separate experiments, lysine-, tyrosine-, glutamine-, and histidine-specific reagents will be added to protein samples. Using combinations of amino acid analysis, amino acid sequencing, and liquid scintillation counting, the extent and locations of modified amino acids will be determined. Successful completion of this aim will provide the basis for a more extended study using acidic proline-rich proteins which, only when adsorbed onto hydroxyapatite, have been shown to bind Actinomyces viscosus, Bacteroides gingivalis, and Streptococcus mutans. The first phase of this project is important in developing the experimental method on small proteins, i.e., statherin and histatin 5, before its general application to the much larger acidic proline-rich proteins. Certain oral microorganisms also bind to statherin in an adsorption-dependent fashion so statherin will serve a useful role the method development. Histatin 5 will be used for the development of histidine modification since statherin does not contain any histidine residues. The ultimate goal of the project will be to determine which amino acids are involved in protein-bacteria interactions.