Identifying Key Structural Interactions in Heparan Sulfate-Protein Complexes

项目摘要 糖胺聚糖（GAG），如硫酸乙酰肝素（HS），是细胞外基质的重要组分。 所有细胞的矩阵。GAG的非凡结构多样性使它们能够与各种各样的生物分子相互作用。 生物分子，但主要是蛋白质，以调节生物过程，如细胞粘附，组织 修复、凝血和免疫反应等。此外，一些不同的病毒， 包括HIV-1，通过与细胞表面GAG结合来启动细胞感染。不幸的是， GAG序列中潜在的结合基序使得相关序列的鉴定具有挑战性。在 特别是硫酸乙酰肝素（HS）是结构上最多样化的，具有16种独特的二糖构型 和256种独特的四糖构型。近年来取得了重大进展， 合成HS寡聚体的文库，允许HS蛋白的详细实验结构研究 配合物了解这些相互作用的结构基础是药物开发和HS的关键 迄今为止，结合蛋白-HS（HSBP-HS）相互作用的研究要么是非结构性的，要么是计算性的。 该项目的总体目标是利用这些最近开发的合成HS库和基于NMR的 结构模型，以确定关键的相互作用。HIV-1 p17将用于初步研究，因为它非常 在HIV-1生命周期的许多阶段都很重要。已知硫酸乙酰肝素受体影响生长 因子信号传导、细胞粘附和人类细胞上的酶催化。因此，这种相互作用可以是以下之一： HIV-1感染者疾病进展的决定因素。在目标1中，合成HS的文库 将筛选四糖与人类免疫缺陷病毒1型（HIV-1）p17蛋白的结合， 鉴定优选结合寡聚体的序列特异性HS特征。在目标2中，HSBP-HS 将通过核磁共振（NMR）研究强结合序列和弱结合序列的复合物 模拟复合物的结构，并确定未来药物开发的关键相互作用。后 方法学建立后，HS结合趋化因子将在目标3中筛选，以确定合适的靶点， 未来的NMR研究

Project Summary Glycosaminoglycans (GAGs), such as heparan sulfate (HS), are important components of the extracellular matrix of all cells. The extraordinary structural diversity of GAGs enables them to interact with a wide variety of biological molecules, but primarily proteins, to modulate biological processes, such as cell adhesion, tissue repair, coagulation, and immune response, among many others. Additionally, a number of different viruses, including HIV-1, initiate infection of cells by binding to cell surface GAGs. Unfortunately, the diversity of potential binding motifs in GAG sequences has made identification of relevant sequences challenging. In particular, heparan sulfate (HS) is the most structurally diverse, with sixteen unique disaccharide configurations and 256 unique tetrasaccharide configurations. Significant progress has been made in recent years developing libraries of synthetic HS oligomers, allowing for detailed experimental structural studies of HS-protein complexes. Understanding the structural basis of these interactions is key to drug development and the HS binding protein-HS (HSBP-HS) interaction studies to date have been either non-structural or computational. The overall goal of this project is to utilize these recently developed synthetic HS libraries and NMR-based structural models to identify key interactions. HIV-1 p17 will be used for initial studies because it is very important in many stages of the life cycle of HIV-1. Heparan sulfate receptors are known to influence growth factor signaling, cell adhesion, and enzymatic catalysis on human cells. Thus, this interaction may be one of the deciding factors for disease progression in humans infected with HIV-1. In Aim 1, a library of synthetic HS tetrasaccharides will be screened for binding to human immunodeficiency virus type 1 (HIV-1) p17 protein to identify the sequence-specific HS characteristics of the preferred binding oligomers. In Aim 2, the HSBP-HS complexes of both strong and weak binding sequences will be studied via nuclear magnetic resonance (NMR) to model the structure of the complex and identify key interactions for future drug development. After the methodology is established, HS-binding chemokines will be screened in Aim 3 to identify suitable targets for future NMR studies.