Platelet alphaIIbbeta3 activation and its therapeutic targeting

血小板αIIbbeta3激活及其治疗靶向

基本信息

批准号：
10469477
负责人：
M. AMIN ARNAOUT
金额：
$ 53.35万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10469477
关键词：
3-Dimensional Adhesions Affinity Agonist Agreement American Binding Binding Sites Biological Availability Blood Platelets Cardiology Cell membrane Cessation of life Collaborations Complex Cryoelectron Microscopy Crystallization Crystallography Cytoplasmic Tail Data Detergents Development Drug Design Drug Targeting Early treatment European Event Excision Face Guidelines Hemorrhage Hemostatic function Heterogeneity Hospitals Immune Impairment Integral Membrane Protein Integrins Leg Length Libraries Life Ligand Binding Ligands Link Measures Membrane Membrane Potentials Methodology Modeling Molecular Conformation Monitor Myocardial Infarction Nature Negative Staining Pathologic Patients Peptide Synthesis Peptides Pharmaceutical Preparations Phase Platelet aggregation Pre-hospital setting Preparation Primates Prior Therapy Proteins Publishing Receptor Activation Recombinants Regulation Reporting Resolution Risk Role Signal Transduction Societies Solid Structure Structure-Activity Relationship Surface Plasmon Resonance Technology Testing Therapeutic Thrombocytopenia Thrombosis Transmembrane Domain Water X-Ray Crystallography adverse outcome antagonist attack victim base clinical efficacy coronary thrombus design eptifibatide high risk improved improved outcome inhibitor insight interdisciplinary approach mimetics mouse model novel percutaneous coronary intervention prevent receptor response small molecule therapeutic target three dimensional structure tomography two-dimensional

3-Dimensional Adhesions Affinity Agonist Agreement American Binding Binding Sites Biological Availability Blood Platelets Cardiology Cell membrane Cessation of life Collaborations Complex Cryoelectron Microscopy Crystallization Crystallography Cytoplasmic Tail Data Detergents Development Drug Design Drug Targeting Early treatment European Event Excision Face Guidelines Hemorrhage Hemostatic function Heterogeneity Hospitals Immune Impairment Integral Membrane Protein Integrins Leg Length Libraries Life Ligand Binding Ligands Link Measures Membrane Membrane Potentials Methodology Modeling Molecular Conformation Monitor Myocardial Infarction Nature Negative Staining Pathologic Patients Peptide Synthesis Peptides Pharmaceutical Preparations Phase Platelet aggregation Pre-hospital setting Preparation Primates Prior Therapy Proteins Publishing Receptor Activation Recombinants Regulation Reporting Resolution Risk Role Signal Transduction Societies Solid Structure Structure-Activity Relationship Surface Plasmon Resonance Technology Testing Therapeutic Thrombocytopenia Thrombosis Transmembrane Domain Water X-Ray Crystallography adverse outcome antagonist attack victim base clinical efficacy coronary thrombus design eptifibatide high risk improved improved outcome inhibitor insight interdisciplinary approach mimetics mouse model novel percutaneous coronary intervention prevent receptor response small molecule therapeutic target three dimensional structure tomography two-dimensional

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项目摘要

Abstract Platelet αIIbβ3 is required for normal hemostasis, but is also a validated drug target because of its essential role in pathologic thrombosis. αIIbβ3 is normally kept in an inactive bent conformation on circulating platelets, but rapidly switches to an active (ligand-binding) conformation in response to inside-out signaling. The ligand- occupied receptor then transmits outside-in signals via the αβ transmembrane (TM) and cytoplasmic domains that initiate platelet adhesion, a response inadvertently produced by current orthosteric inhibitory drugs, which has limited their clinical efficacy. The structural basis of bidirectional integrin signaling remains to be clarified. One model suggests that the ligand-binding site directly faces the plasma membrane in the bent conformation, with integrin genuextension required for access to ligand. However, the integrin ectodomain/TM tilt has not been defined experimentally. Further, regulated αβ TM domain association in integrins is driven by the ectodomain, which may explain some of the differences found in the reported NMR structures of the isolated αIIbβ3 TM domains. In preliminary studies, we produce a low-resolution cryo-EM structure of full-length αIIbβ3 in an unexpected orientation relative to the membrane, the result of its complex in cis with a tetraspanner, providing the first experimental definition of an integrin ectodomain/TM tilt, and novel insights into the structural basis of αIIbβ3 activation. We also develop a water soluble, stable and high affinity orthosteric inhibitor of αIIbβ3 that is not a partial agonist, and use it in a structure-guided approach to generate like compounds. We propose to expand on these preliminary data in three specific aims, utilizing multidisciplinary approaches that include electron cryomicroscopy, tomography, protein crystallography, structure-based drug design, new peptide synthesis technology and novel murine models of thrombosis.

抽象的正常止血需要血小板αIIBβ3，但也是经过验证的药物靶标的在病理血栓形成中的作用。 αIIBβ3通常将循环血小板上的无活性的屈光度组成保存在但是，响应内而外的信号传导，快速切换到活性（配体结合）构象。配体 - 然后，被占据的受体通过αβ跨膜（TM）和细胞质结构域传输外部信号启动血小板粘附，这是由当前正常抑制性药物无意中产生的反应，限制了他们的临床效率。双向整联蛋白信号传导的结构基础尚待澄清。一个模型表明，配体结合位点直接面对弯曲构象中的质膜，使用整合素的真实延迟才能进入配体。但是，整联蛋白Ectodomain/tm倾斜尚未是通过实验定义的。此外，整联蛋白中调节的αβTM结构域的关联是由外生域，这可以解释分离的NMR结构中发现的一些差异 αIIBβ3TM结构域。在初步研究中，我们产生了全长αIIBβ3的低分辨率冷冻EM结构在相对于膜的意外取向中，其复合物在CIS中与四面式的结果，提供整联蛋白Ectodomain/tm倾斜的第一个实验定义，以及对 αIIBβ3活化的结构基础。我们还开发了固体，稳定和高亲和力的水不是部分激动剂的αIIBβ3的抑制剂，并以结构引导的方法使用它来产生类似化合物。我们建议使用多学科的三个特定目标扩展这些初步数据包括电子冷冻显微镜，断层扫描，蛋白质晶体学，基于结构的药物的方法设计，新的肽合成技术和血栓形成的新型鼠模型。