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（由申请人提供）：已经确定蛋白质（及其肽产物）仅使用L-氨基酸进行核糖体翻译，因此假设D-氨基酸天然不存在于动物肽中。 ，生理性含 D-氨基肽 (DAACP) 确实存在，首先在青蛙中发现，是由翻译后修饰产生的：肽异构化，但是，因为它们没有相关的质量转移，DAACP。历史上很难识别，导致质谱驱动的肽表征研究存在差距。拟议工作的目标是通过开发利用 DAACP 独特特性（包括其对降解的抵抗力）来检测 DAACP 的工具来弥补这一差距。此外，DAACP 的形成会改变肽的形状，从而改变其与受体结合的能力，这对于神经肽（通过与其同源物结合而具有生物活性的细胞间信号分子）尤其重要。因此，在具体目标 1 中，将使用来自较简单模型动物的神经肽来开发识别 DAACP 的工具，其中已经鉴定了一种 DAACP 发现系统涉及手性分析：将内源性神经肽分解为其成分。作为国家药物滥用研究所 (NIDA) 的一部分，这项工作的长期目标是鉴定哺乳动物神经系统中的功能性 DAACP。程序领域，它对神经递质（如神经肽）的功能感兴趣 尽管进行了深入的研究，但仍有超过 100 种人类 G 蛋白偶联受体没有已知的结合伴侣，这可以部分解释通过基因组和肽组学研究已知的神经肽数量与大量孤儿肽之间的差异。对于拟议的工作，在具体目标 2 中，将研究神经肽在视交叉上核 (SCN)（下丘脑神经元组）的背景下的肽异构化。 SCN 是针对神经肽在一天中的释放时间进行的广泛研究，并且已经在 SCN 中鉴定出许多肽酶抗性肽，这项工作意义重大，因为 NIDA 已经发现了睡眠障碍。由于与药物滥用有关，因此被忽视的 PTM 可能导致我们的睡眠/觉醒周期中许多神经肽功能缺失。DAACP 作为哺乳动物神经肽中的一种生理现象的发现最终有助于实现这一目标。通过识别药物滥用背后的神经回路的功能特性来了解药物滥用的目标。