STRUCTURAL BASIS OF CHEMOKINE RECEPTOR RECOGNITION

趋化因子的生物学功能严重依赖于它们对特定G蛋白偶联受体（gpcr）的识别和激活。该项目的总体目标是了解趋化因子及其受体之间的结构相互作用。不幸的是，由于全长gpcr的工作困难，这些相互作用不能通过x射线晶体学或核磁共振（NMR）光谱直接观察到。诱变研究已经确定了参与功能性蛋白质-蛋白质相互作用的残基，但导致受体识别和激活的确切相互作用仍未确定。所提出的研究中采用的方法试图通过使用从趋化因子受体的细胞外结构域衍生的合成肽重建识别界面来规避这一问题。这些基于受体的多肽的构象及其与溶液中的趋化因子的相互作用将使用圆二色性和核磁共振光谱进行表征。多肽的生物活性将通过体外中性粒细胞趋化性和受体结合测定来确定。将对数据进行分析，以开发趋化因子受体识别的结构模型，该模型将使用位点定向诱变进行测试，然后进行功能分析。对趋化因子受体识别的结构基础的研究与人类健康和疾病有着广泛的相关性。趋化因子在多种过敏性和风湿病（包括哮喘、关节炎和牛皮癣）中起主要作用。趋化因子对动脉粥样硬化、血管生成和肿瘤生长的影响已有报道。一些趋化因子受体作为HIV-1的辅助受体，已经成为鉴定新的抗hiv化合物的有吸引力的靶点。受体识别模型将指导实验来描述特定趋化因子受体相互作用的生物学作用。此外，治疗剂可以合理设计，以精确抑制与疾病有关的单对趋化因子及其受体。拟议的项目将在Dr. Elias Lolis的实验室进行，这将使我能够继续我在蛋白质结构生物学方面的培训，并向我介绍免疫生物学的科学和技术。通过这次培训，我的职业发展将得到加强，并为我将来从事学术医学研究做好准备。

The biological function of chemokines is critically dependent on their recognition and activation of specific G protein coupled receptors (GPCRs). The overall goal of the proposed project is to develop an understanding of the structural interactions between chemokines and their receptors. Unfortunately, these interactions cannot be directly observed by X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy due to the difficulty of working with full-length GPCRs. Mutagenesis studies have identified residues that are involved in functional protein-protein interactions, but the precise interactions that result in receptor recognition and activation remain uncharacterized. The approach adopted in the proposed research attempts to circumvent this problem by reconstructing the recognition interface using synthetic peptides derived from the extracellular domains of chemokine receptors. The conformation of these receptor-based peptides and their interactions with chemokines in solution will then be characterized using circular dichroism and NMR spectroscopy. The biological activity of the peptides will be determined using in vitro assays of neutrophil chemotaxis and receptor binding. The data will be analyzed in order to develop a structural model of chemokine receptor recognition which will be tested using site-directed mutagenesis, followed by functional assays. Research into the structural basis of chemokine receptor recognition has wide-ranging relevance to human health and disease. Chemokines play a predominant role in a variety of allergic and rheumatic diseases including asthma, arthritis and psoriasis. Effects of chemokines on atherogenesis, angiogenesis and tumor growth have been reported. Some of the chemokine receptors function as HIV-1 coreceptors and have become attractive targets for identifying new anti-HIV compounds. A model of receptor recognition will guide experiments to delineate the biological roles of specific chemokine-receptor interactions. As well, therapeutic agents could be rationally designed to precisely inhibit single pairs of chemokines and their receptors which are specifically implicated in disease. The proposed project to be performed in the laboratory of Dr. Elias Lolis will allow me to continue my training in protein structural biology as well as introduce me to the science and techniques of immunobiology. My career development will be enhanced by this training and will prepare me for a future career in academic medical research.