Protein Modification: Isoaspartic Acid

蛋白质修饰：异天冬氨酸

• 批准号: 8275695
• 负责人: ZHAOHUI SUNNY ZHOU
• 金额: $ 27.86万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8275695
• 关键词: Aging; Alleles; Alzheimer' s Disease; Amyloid beta-Protein; Animals; Antibodies; Area; Asparagine; Aspartic Acid; Autoimmune Diseases; Autoimmunity; Binding; Biochemical; Biochemistry; Biological Assay; Biological Markers; Brain; Chemistry; Complement; Disease; Engineering; Ensure; Enzymatic Biochemistry; Enzyme Kinetics; Eye; Fission Yeast; Goals; Human; Immunology; In Situ; Individual; Intervention; Isoaspartic Acid; Knock-out; Knowledge; Label; Lead; Libraries; Mass Spectrum Analysis; Measurement; Medical; Metabolic Pathway; Methionine; Methodology; Methods; Methylation; Methyltransferase; Molecular Models; Mus; Nerve Degeneration; Neurodegenerative Disorders; Nutritional Biochemistry; Peptide Library; Peptides; Positioning Attribute; Post-Translational Protein Processing; Preventive Intervention; Process; Protein Analysis; Protein Chemistry; Proteins; Proteomics; Rattus; Regulation; Research; Role; Saccharomyces cerevisiae; Sampling; Screening procedure; Signal Transduction; Structural Models; Substrate Specificity; System; Systemic Lupus Erythematosus; Vertebral column; Vitamin B 12 Deficiency; adduct; age related; analog; beta-Aspartate; crosslink; deamidation; enzyme activity; genome wide association study; human disease; interest; molecular modeling; mutant; novel strategies; protein structure function; repair enzyme; structural biology; transmethylation

DESCRIPTION (provided by applicant): Our long-term goal is to better understand the etiologic roles of protein posttranslational modifications (PTMs). This project focuses on isoaspartic acid (isoAsp, isoD or beta-Asp), which is generated spontaneously from either asparagine deamidation or aspartic acid isomerization. IsoAsp has been found in myriad proteins (e.g., beta-amyloid in the brain and crystalline in the eyes). Notably, isoAsp imparts a D-configuration and beta-linkage into the peptide backbone; such alteration of peptide backbones is exceptionally rare and may drastically alter protein structure and function. While well-recognized in aging, its emerging roles in signaling, regulation and autoimmunity have yet been widely appreciated. A lack of comprehensive knowledge of isoAsp and the unique technical challenges in its analysis hamper progress in this field. For one thing, isoAsp formation is the smallest PTM by mass change (Da; isoAsp has the same mass as Asp). Recently, these technical barriers have been overcome by novel approaches that combine chemo-enzymatic labeling and enrichment with mass spectrometry. Four specific aims will be undertaken. First, proteomic analysis of isoAsp in samples with biochemical and medical relevance will be performed. Second, tight binders to isoAsp will be engineered and used as antibodies for applications that complement existing methodologies. Third, the substrate specificity of the repair enzyme protein isoaspartate methyltransferase (PIMT) will be probed, focusing most assiduously on poor substrates of PIMT. Isoaspartyl peptide library screening, enzyme kinetic characterization, proteomic analysis and protein structural modeling will be integrated to augur the fate of isoAsp in individual proteins and whole systems. Last, alternative metabolic pathways for isoAsp will be discovered. The proposed research will lead to the discovery of biomarkers of human diseases, and effective methods of prevention, intervention and treatment for age-related conditions, neurodegenerative disorders (e.g., Alzheimer's disease), autoimmune diseases and other isoAsp-related ailments. PUBLIC HEALTH RELEVANCE: Isoaspartic acid formation is one of the most common, yet under-appreciated, modifications of proteins, and may significantly alter protein structures and functions. A comprehensive knowledge of this ubiquitous protein modification will advance both our understanding of the etiological mechanism and the intervention of diseases, particularly neurodegenerative and age-related disorders.

描述（由申请人提供）：我们的长期目标是更好地了解蛋白质后翻译后修饰（PTMS）的病因作用。该项目的重点是异质酸（ISOASP，ISOD或β-ASP），该项目是由天冬酰胺脱氨酸或天冬酸异构化自发产生的。 ISOASP已在无数蛋白质（例如，大脑中的β-淀粉样蛋白和眼睛的结晶）中发现。值得注意的是，ISOASP将d-configuration和β-连接授予肽主链。这种肽骨架的这种改变异常罕见，可能会大大改变蛋白质的结构和功能。尽管在衰老方面得到了充分的认可，但它在信号，调节和自身免疫性中的出现角色尚未得到广泛的欣赏。缺乏对ISOASP的全面知识以及其分析中的独特技术挑战阻碍了该领域的进步。一方面，isoasp编队 是质量变化最小的PTM（da; isoasp具有与ASP相同的质量）。最近，通过将化学酶标记和富集与质谱法结合的新方法克服了这些技术障碍。将实现四个具体目标。首先，将对具有生化和医学相关性的样品中的ISOASP进行蛋白质组学分析。其次，对ISOASP的紧密粘合剂将被设计并用作补充现有方法的应用的抗体。第三，将探测修复酶蛋白异甲基转移酶（PIMT）的底物特异性，最顽固地集中在PIMT较差的底物上。等异冬型肽库筛选，酶动力学表征，蛋白质组学分析和蛋白质结构建模将被整合，以增强单个蛋白质和整个系统中ISOASP的命运。最后，将发现ISOASP的替代代谢途径。拟议的研究将导致发现人类疾病的生物标志物，以及针对年龄相关疾病，神经退行性疾病（例如，阿尔茨海默氏病），自身免疫性疾病和其他ISOAPSASP相关疾病的有效预防，干预和治疗方法。 公共卫生相关性：同甲酸的形成是蛋白质的最常见，但被低估的修饰之一，可能会显着改变蛋白质结构和功能。对这种无处不在的蛋白质修饰的全面知识将提高我们对病因机制和疾病干预的理解，尤其是神经退行性和与年龄有关的疾病。