TERTIARY STRUCTURES OF SALIVARY PROTEINS

唾液蛋白的三级结构

• 批准号: 3425745
• 负责人: MARK S LAMKIN
• 金额: $ 4.11万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1994-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3425745
• 关键词: adsorption; aminoacid analyzer; binding proteins; conformation; high performance liquid chromatography; human subject; hydroxyapatites; parotid gland; pellicle; protein purification; protein sequence; protein structure; protein structure function; saliva; tooth enamel

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.

腮腺、颌下腺和舌下腺的分泌物含有 大量的蛋白质，并且可以选择性地吸附到 牙釉质的类似羟基磷灰石的表面。 一旦吸附到 牙齿表面，这些蛋白质可能参与 牙齿表面的脱矿/矿化。 另外这些 蛋白质可能表现出受体样结构域，这在早期 可能涉及特定口腔微生物的定植， 龋齿和/或牙周病。 有重要证据表明， 表明某些唾液蛋白的受体样结构域不是 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 生物化学和显微技术表明， 细菌结合位点周围的变化。 然而，这些技术 受限于其低分辨率。 一种新的策略， 研究其他蛋白质复合物的构象变化， 为了确定地点， 构象变化，可能解析为特定氨基酸 残余物 这项建议的具体目标是： 为了进行共价蛋白质修饰的氨基酸侧链， 和/或组胺素5，并测定氨基酸 溶液中标记的蛋白质与标记的蛋白质之间的反应性 然后吸附到羟基磷灰石上。 在不同的实验中， 赖氨酸、酪氨酸、谷氨酰胺和组氨酸特异性试剂将被 添加到蛋白质样品中。 使用氨基酸分析的组合，氨基 酸测序和液体闪烁计数，程度和 将确定修饰的氨基酸的位置。 成功地完成这一目标将为进一步加强 使用富含脯氨酸的酸性蛋白质进行的扩展研究， 附着在羟基磷灰石上，已经证明可以结合粘性放线菌， 牙龈拟杆菌和变形链球菌。 的第一阶段 项目是重要的，在发展实验方法的小 蛋白质，即，在其普遍应用于 大得多的富含脯氨酸的酸性蛋白质。 某些口腔微生物 也以依赖于吸附的方式与Statherin结合， 为方法的发展起到了有益的作用。 Histatin 5将用于 组氨酸修饰的发展，因为他他色林不含 任何组氨酸残基。 该项目的最终目标将是 确定哪些氨基酸参与蛋白质-细菌相互作用。