ANALYSIS OF PROLINE RICH PROTEINS FROM HUMAN SALIVA

人类唾液中富含脯氨酸的蛋白质的分析

• 批准号: 7369223
• 负责人: Frank G Oppenheim
• 金额: $ 0.09万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7369223
• 关键词: ANALYSIS; PROLINE; RICH; PROTEINS; HUMAN

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Proline-rich proteins (PRPs) are a family of salivary proteins present in abundant amounts in human parotid and submandibular/sublingual secretions and account for 10-40% of the proteins in these secretions (Kousvelari et al., 1980; Baum et al., 1982; Mandel & Bennick 1983). On the basis of their chemical properties, they are divided into three groups, acidic, basic and glycosylated PRPs. The acidic PRPs are a group of eight structurally closely related molecules with pIs between 4 and 5 (Oppenheim et al., 1971; Bennick and Connell, 1971; Hay et al., 1988). PIFs, PRP1, PRP2 contain 150 residues and have the same amino acid sequence except at positions 4 and 50, which are either aspartic acid or asparagine. PIFf, PRP3 and PRP4 are composed of 106 residues and are identical with the N-terminal 106 residues of PIFs, PRP1 and PRP2, respectively. Genetic studies revealed that the sequence of PRP ?Pa? is identical to PIFs except for the residue at position 27 where leucine substitutes for isoleucine and the residue at position 103 where cysteine substitutes for arginine (Azen et al., 1987). Another acidic PRP characterized by genetic analysis was the ?Db? protein that would contain an extra 21 amino acid repeat of residues 61-81 of PIFs resulting in a 171-amino acid residue polypeptide chain (Azen et al., 1987). The acidic PRPs exhibit unusual biochemical characteristics. They are rich in the amino acids glycine, proline, glutamine and glutamic acid. Amino acid sequencing and chemical analysis has shown that both the serines at residues 8 and 22 are phosphorylated in PIFs, PIFf, PRP1, PRP2, PRP3 and PRP4. Due to the high degree of sequence homology and close pI values of PRPs, separation of these proteins requires chromatography with extremely high resolution and usually involves at least two steps, using a combination of gel filtration and anion-exchange chromatographic techniques. This purification scheme is not only cumbersome, but often results in protein contaminants and unwanted protein loss. Furthermore, these procedures make it impractical to quantitate different PRPs in a number of individuals. The present investigation has resulted in the development of a one step procedure to separate the 8 acidic PRP isoforms and characterized the primary structure and post-translational modifications of the Pa and Db proteins. A manuscript reporting these results will be submitted shortly.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。富含脯氨酸的蛋白质（PRP）是人腮腺和下颌/舌下分泌物中大量存在的唾液蛋白家族，在这些分泌物中占10-40％的蛋白质（Kousvelari等，1980; Baum et al。，Mandel＆Bennick＆Bennick 1983）。根据其化学特性，它们分为三组，酸性，碱性和糖基化PRP。酸性PRP是一组由4到5之间的八个结构密切相关的分子组成的（Oppenheim等，1971; Bennick and Connell，1971; Hay等，1988）。 PIF，PRP1，PRP2包含150个残基，除位于4和50的位置外，其氨基酸序列是天冬氨酸或天冬酸酯。 PIFF，PRP3和PRP4由106个残基组成，与PIFS，PRP1和PRP2的N末端106个残基相同。遗传研究表明PRP？PA的序列？除了位于27位的残基外，亮氨酸替代异亮氨酸和103位的残基，在103位的残基，其中半胱氨酸的替代品（Azen等，1987）。另一个以遗传分析为特征的酸性PRP是？db？蛋白质会含有额外的21个氨基酸重复，残基61-81的PIF，导致171-氨基酸残基多肽链（Azen等，1987）。酸性PRP表现出异常的生化特征。它们富含氨基酸甘氨酸，脯氨酸，谷氨酰胺和谷氨酸。氨基酸测序和化学分析表明，残基8和22的丝氨酸在PIF，PIFF，PRP1，PRP2，PRP3和PRP4中均磷酸化。由于PRP的序列同源性高度高度和PI值，这些蛋白质的分离需要具有极高分辨率的色谱法，并且通常涉及至少两步，使用凝胶过滤和阴离子 - 交换色谱技术的组合。这种纯化方案不仅繁琐，而且通常会导致蛋白质污染物和不需要的蛋白质丧失。此外，这些程序使得在许多个体中量化不同的PRP是不切实际的。本研究导致开发了一个步骤，以分离8种酸性PRP同工型，并表征了PA和DB蛋白的主要结构和翻译后修饰。报告这些结果的手稿将很快提交。