Quantum Dot Nanoconjugate Imaging of Neural Receptors

描述（由申请人提供）：受体驱动的细胞行为，范围从神经活动中的信号传导和兴奋性到免疫系统对疾病侵袭的反应，代表了生物系统中一类重要的功能性纳米生物结构。由于受体能够通过配体结合来感知环境，并且能够通过信号级联将该信号传递到细胞内部，因此受体独特地适合于指导这样的过程。该提案的目标是开发新的成像工具和方法，以建立对生物受体功能的定量分子水平理解。不幸的是，这些基本的生物成分的研究是有限的，目前可用的成像工具，如放射性标记的配体或间接检测通过抗体。这些方法由于放射性示踪剂研究的空间分辨率差、膜蛋白的表面结构域抗体探针的有限可用性、可用荧光团的宽发射光谱及其光化学降解而受到影响。在这项提案中，我们将继续发展我们的新的，非同位素，标记策略涉及配体共轭荧光纳米晶体（nanoconjugates）。具体而言，我们将： 1.设计、合成和表征用于成像神经受体的新型纳米缀合物探针。 2.发展纳米结合物-受体相互作用的分子水平的理解。 3.演示神经递质受体的动态成像，以绘制其调节和功能。 为了实现这些具体目标，我们组建了一个多学科团队，包括化学家，物理学家，药理学家和神经科学家。完成这一授权将导致一类新的基于高荧光小分子和肽共轭的CdSe/ZnS核壳纳米晶体的纳米共轭物的开发。这些探针将使神经科学和膜生物学的研究人员能够回答以前由于当前方法的限制而无法回答的问题。本文所述的纳米缀合物提供了对涉及神经G蛋白偶联受体和转运蛋白的基本过程进行动态成像的机会。这种"真实的时间"实验将为这些神经受体的分子细节、它们对外部刺激的反应的运输和定位提供新的见解。这些结果将为抑郁、成瘾和学习等神经过程提供新的分子水平的见解。此外，纳米缀合物可以作为新药物发现方法的基础，以鉴定靶向先前与神经系统疾病有关的特定受体的独特药物。

DESCRIPTION (provided by applicant): Receptor driven cellular behavior, ranging from signaling and excitability in neural activity to immune system response to disease invasion, represents an important class of functional nanobiostructures in biological systems. Receptors are uniquely suited to direct such processes due to their ability to sense the environment, through ligand binding, and their ability to transmit this signal to the cell interior via signal cascades. The goal of this proposal is the development of novel imaging tools and methods to establish a quantitative molecular level understanding of the function of biological receptors. Unfortunately, the study of these fundamental biological components is limited by currently available imaging tools such as radiolabeled ligands or indirect detection via antibodies. These approaches suffer due to the poor spatial resolution of radiotracer studies, the limited availability of surface-domain antibody probes for membrane proteins, the broad emission spectra of available fluorophores and their photochemical degradation. In this proposal, we will continue to develop our novel, non-isotopic, labeling strategy involving ligand-conjugated fluorescent nanocrystals (nanoconjugates). Specifically, we will: 1. Design, synthesize, and characterize novel nanoconjugate probes for imaging neural receptors. 2. Develop a molecular level understanding of nanoconjugate-receptor interactions. 3. Demonstrate dynamic imaging of neurotransmitter receptors in order to map their regulation and function. To accomplish these specific aims, we have assembled a multidisciplinary team including chemists, physicists, pharmacologists and neuroscientists. Completion of this grant will result in the development of a novel class of nanoconjugates based on highly fluorescent small-molecule and peptide conjugated CdSe/ZnS core shell nanocrystals. These probes will enable investigators in neuroscience and membrane biology to answer questions previously unanswerable due to the limitations of current methods. The nanoconjugates described herein present the opportunity for dynamic imaging of fundamental processes involving neural G protein-coupled receptors and transporter proteins. Such "real time" experiments will provide new insight into questions concerning the molecular details of these neuroreceptors, their trafficking and localization in response to external stimuli. Such results will provide new molecular level insights into neural processes such as depression, addiction and learning. Additionally, the nanoconjugates may serve as the basis for new drug discovery methods to identify unique drugs that target specific receptors previously implicated in neurological disorder.