Identification of D-amino acid-containing peptides in the nervous system

神经系统中含 D-氨基酸肽的鉴定

• 批准号: 8835376
• 负责人: Itamar Livnat
• 金额: $ 4.81万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-16 至 2019-02-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8835376
• 关键词: Affect; American; Amino Acids; Analytical Chemistry; Animal Model; Animals; Aplysia; Area; Behavior; Binding; Biological Assay; Circadian Rhythms; Detection; Distant; Drosophila genus; Drug Addiction; Drug abuse; G-Protein-Coupled Receptors; Genes; Genomics; Goals; Human; Hypothalamic structure; Isomerase; Knowledge; Link; Mammals; Mass Spectrum Analysis; Methods; Modeling; Modification; Moods; National Institute of Drug Abuse; Nervous system structure; Neurons; Neuropeptides; Neurotransmitters; Organism; Ornithorhynchus anatinus; Orphan; Outcome; Peptide Hydrolases; Peptide Receptor; Peptides; Pharmacologic Substance; Physiological; Post-Translational Protein Processing; Process; Property; Proteins; Rana; Research; Resistance; Rodent; Role; Shapes; Signal Pathway; Signal Transduction; Signaling Molecule; Sleep Disorders; Sleep Wake Cycle; Structure; System; Techniques; Testing; Time; Toxin; Translating; Work; base; cohort; drug development; drug of abuse; drug relapse; instrumentation; intercellular communication; interest; neural circuit; novel; peptide structure; programs; public health relevance; receptor; suprachiasmatic nucleus; three dimensional structure; tool

 DESCRIPTION (provided by applicant): It has been established that proteins (and thus, their peptide products) are ribosomally translated using only L-amino acids, and so it was assumed that D-amino acids did not naturally exist in animal peptides. However, physiological D-amino containing-peptides (DAACP) do exist, first identified in frogs, resulting from a post-translationa modification: peptide isomerization. However, because they have no associated mass shift, DAACPs are historically very difficult to identify, causing a gap in mass spectrometry-driven peptide characterization studies. The objective of the proposed work aims to bridge this gap by developing tools to detect DAACPs by taking advantage of their unique properties, including their resistance to degradation by peptidases. In addition, formation of a DAACP alters the shape of a peptide, which can change its ability to bind to a receptor. This is especially important for neuropeptides, cell-cell signaling molecules that are bioactive by binding to their cognate receptor. Thus, in specific aim 1, the tools to identify DAACPs will be developed using neuropeptides from a simpler model animal, where one DAACP has already been identified. This system of DAACP discovery involves chiral analysis: breaking down an endogenous neuropeptide into its component amino acids and assaying those amino acids for their chirality using analytical chemistry methods. The long-term objective of this work is to identify functional DAACPs in the mammalian nervous system. As part of the National Institute on Drug Abuse (NIDA) program areas, it is interested in the function of neurotransmitters (like neuropeptides) in endogenous systems. In spite of intensive study, more than 100 human G-protein coupled receptors have no known binding partner. DAACPs may explain, in part, the discrepancy between the number of neuropeptides known through genomic and peptidomic studies and the large number of orphan receptors. For the proposed work, in specific aim 2, neuropeptides will be studied for peptide isomerization in the context of the suprachiasmatic nucleus (SCN), a hypothalamic group of neurons with a known role in circadian rhythms. The SCN is targeted because there are extensive studies on time of day release of neuropeptides and a number of peptidase-resistant peptides have already been identified in the SCN. This work is significant because NIDA has identified sleep disorders as having a link to drug abuse, so the implication of an overlooked PTM can result in many missed neuropeptide functions in our sleep/wake cycles. The discovery of DAACPs as a physiological phenomenon in mammalian neuropeptides ultimately helps reach the goal of understanding drug abuse by identifying the functional properties of neural circuits underlying drug abuse.

 描述（由应用提供）：已经确定蛋白质（因此，其肽产物）仅使用L-氨基酸进行核糖体翻译，因此假定在动物肽中不存在D-氨基酸。但是，确实存在含有物理D-氨基肽的物理D-氨基肽（DAACP），这是在青蛙中首先鉴定出的，这是由翻译后修饰引起的：肽异构化。但是，由于它们没有相关的质量转移，因此DAACP在历史上很难识别，从而导致质谱驱动的肽表征研究差距。拟议工作的目的旨在通过利用其独特的特性（包括对Petidass对降解的抵抗力）来开发用于检测DAACP的工具来弥合这一差距。另外，DAACP的形成会改变肽的形状，从而改变其与受体结合的能力。对于神经肽，通过与其同源受体结合而具有生物活性的细胞 - 细胞信号分子尤其重要。在特定的目标1中，将使用来自简单模型动物的神经肽开发识别DAACP的工具，该动物已经确定了一个DAACP。 DAACP发现系统涉及手性分析：将内源性神经肽分解为其成分氨基酸，并使用分析化学方法主张这些氨基酸的手性。这项工作的长期目标是识别哺乳动物神经系统中的功能性DAACP。作为美国国家药物滥用研究所（NIDA）计划领域的一部分，它对神经递质（如神经肽）的功能感兴趣 内源系统。尽管进行了密集研究，但100多个人类G蛋白偶联受体没有已知的结合伴侣。 DAACP可以部分解释通过基因组和肽组研究已知的神经肽数量与大量孤儿受体之间的差异。对于拟议的工作，在特定的目标2中，将研究神经肽在Suroparchiasmamatic Nucus（SCN）的背景下进行肽异构化，这是一种在昼夜节律中具有已知作用的神经元组。 SCN之所以成为针对性的，是因为在一天中的神经肽的时间释放中进行了广泛的研究，并且在SCN中已经鉴定出了许多耐肽的肽。这项工作很重要，因为NIDA已将睡眠障碍确定为与药物滥用有联系，因此被忽视的PTM的含义可能导致我们的睡眠/唤醒周期中许多错过的神经肽功能。在哺乳动物神经肽中发现DAACP是一种物理现象，最终有助于实现了解药物滥用潜在的神经元电路的功能性能，以实现了解药物滥用的目标。