Quantum Dot Nanoconjugate Imaging of Neural Receptors

描述（由申请人提供）：受体驱动的细胞行为，从神经活动的信号和兴奋性到免疫系统对疾病入侵的反应，代表了生物系统中重要的一类功能纳米生物结构。受体是唯一适合于指导这些过程的，因为它们有能力感知环境，通过配体结合，并通过信号级联将信号传递到细胞内部。本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，这些基本生物成分的研究受到目前可用的成像工具的限制，如放射性标记配体或通过抗体间接检测。由于放射性示踪剂研究的空间分辨率较差，膜蛋白表面结构域抗体探针的可用性有限，可用荧光团的发射光谱广泛及其光化学降解，这些方法受到影响。在本提案中，我们将继续开发涉及配体共轭荧光纳米晶体（纳米共轭物）的新型非同位素标记策略。具体而言，我们将：

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.