Kinetic Mechanical Properties of aLb2 Integrin

aLb2 整合素的动力学机械特性

• 批准号: 7570607
• 负责人: Cheng Zhu
• 金额: $ 36.89万
• 依托单位: GEORGIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7570607
• 关键词: Adhesions; Affinity; Atomic Force Microscopy; Binding; Binding Sites; Biochemical; Biological Process; Blood Vessels; C-terminal; Cell Adhesion Molecules; Cells; Characteristics; Complement; Complex; Development; Divalent Cations; Drug or chemical Tissue Distribution; Elasticity; Event; Family; Figs - dietary; Goals; Grant; Hydrophobic Interactions; Inflammation; Integrins; Intercellular adhesion molecule 1; Kinetics; Leukocytes; Ligand Binding; Ligands; Lymphocyte Function-Associated Antigen-1; Measurement; Measures; Mechanics; Mediating; Membrane; Methods; Modeling; Molecular; Molecular Conformation; Molecular Models; Monoclonal Antibodies; Movement; Muscle Rigidity; Nature; Pharmaceutical Preparations; Pharmacologic Substance; Process; Property; Recording of previous events; Regulation; Reporting; Research; Resolution; Role; Selectins; Simulate; Solutions; Structure; Surface; Surface Plasmon Resonance; Techniques; Time; Variant; Work; base; migration; molecular dynamics; molecular modeling; mutant; receptor; research study; single molecule; small molecule; trafficking; two-dimensional

DESCRIPTION (provided by applicant): Our long-term goal is to enable quantitative prediction and control of leukocyte adhesion to vascular surface during inflammation and trafficking. This multistep process requires interactions of selectins, which mediate tethering and rolling adhesion, and integrins, which mediate stable adhesion. The focus of the previous grant period was selectins. We used the micropipette, atomic force microscopy, and flow chamber experiments to analyze their kinetic and mechanical properties. We propose to extend this work to alphaLbeta2 integrin in the present application. Compared to selectins, integrins are a larger family of adhesion molecules, have a broader tissue distribution, and mediate a wider variety of biological functions. Integrins provide mechanical linkage between cells so their ligand binding kinetics and affinity are relevant. Such kinetics and affinity are regulated by force and conformation, so mechanics is important. Yet there have only been a handful of studies reporting the single molecule kinetic and mechanical measurements on integrins. Using a variety of mutants provided by the Springer lab, we propose to employ kinetic and mechanical measurements as well as molecular modeling and molecular dynamics simulations to elucidate the regulation of integrin function by conformational changes. Specifically, we will measure and simulate the effects of structural variations in alphaL I domain on its 2D binding kinetics and affinities, to characterize the global conformational states of alphaLbeta2 and induced transitions among different states using kinetic and mechanical measurements, and to quantify the regulation of 2D kinetics of WT and mutant aL I domains and alphaLbeta2 integrin by activating/inhibitory agent. Not only will the information generated from this research advance our understanding of the workings of integrins, but it may also provide guidance to the development of integrin-based drugs that is currently being actively pursued by many biotechnological and pharmaceutical companies.

描述（由申请人提供）：我们的长期目标是在炎症和运输过程中对白细胞粘附对血管表面的粘附进行定量预测和控制。这种多步过程需要选择蛋白的相互作用，这些相互作用介导链接和滚动的粘附以及整合素，从而介导稳定的粘附。上一个赠款期的重点是Selectins。我们使用了微孔，原子力显微镜和流室实验来分析其动力学和机械性能。我们建议将此工作扩展到本应用程序中的alphalbeta2整合蛋白。与选择素相比，整联蛋白是较大的粘附分子家族，具有更广泛的组织分布，并介导了更广泛的生物学功能。整联蛋白在细胞之间提供机械连接，因此其配体结合动力学和亲和力是相关的。这种动力学和亲和力受力和构象的调节，因此机理很重要。然而，只有少数研究报告了整合素的单分子动力学和机械测量。使用Springer Lab提供的多种突变体，我们建议采用动力学和机械测量以及分子建模和分子动力学模拟，以通过构象变化来阐明整合素功能的调节。具体而言，我们将测量和模拟Alphal I结构域对其2D结合动力学和亲和力的结构变化的影响，以表征α2的全球构象状态，并使用动力学和机械测量结果在不同状态之间进行诱导的过渡，并量化量化的过渡。 WT和突变体I域和α2整合素的2D动力学通过激活/抑制剂。从这项研究中产生的信息不仅可以提高我们对整联蛋白起作用的理解，而且还可以为开发基于整合素的药物的开发提供指导，这些药物目前正在许多生物技术和制药公司积极寻求。