Developing High Resolution NMR Field Cycling as a Probe of Phospholipid Dynamics

开发高分辨率核磁共振场循环作为磷脂动力学的探针

• 批准号: 0517381
• 负责人: Mary Roberts
• 金额: --
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0517381&HistoricalAwards=false
• 关键词: Developing; Resolution; NMR; Field; Cycling

High resolution field cycling NMR methods will be developed as robust tools for studying the dynamics and headgroup orientation of phospholipids in model membranes. Initial work will test assumptions made in data reduction and interpretation of preliminary 31P studies. This will require synthesis of phospholipids where different segments have been deuterated, as well as comparisons of field cycling NMR data for model systems to molecular dynamic simulations to identify bilayer motions contributing to the relaxation rates. Field cycling relaxation results will also be compared to those from standard fixed field T1r measurements. Once validated, the field cycling methods will be used to examine lipid headgroup conformation and lateral interactions in multicomponent vesicles and aggregates with additives such as Ca2+ or cholesterol, characterize the specific interactions of two peripheral proteins, annexin V and Streptomyces chromofuscus phospholipase D, that exhibit kinetic or binding specificity for a given headgroup phospholipid in multicomponent vesicles, and assess the effect of a transmembrane helical peptide, WALP16, on phosphate conformation and dynamics. While examination of these diverse systems should provide a critical evaluation of the usefulness of the methodology, the results themselves will provide detailed information on how the two peripheral proteins and the transmembrane helix affect the dynamics and conformation of the phosphate moiety of phospholipids in multicomponent systems.Both undergraduate and graduate students will be trained in NMR theory and experiments. One-on-one contact in the laboratory with the PI and collaborators will help produce the next generation of researchers and science educators. The dissemination of the results of this research will introduce the NMR community to a powerful new method, easy to implement with conventional spectrometers, that is optimal for characterizing diverse phospholipid aggregates and phospholipid/protein interactions. The quantitative information on the dynamics and conformation of the phosphate moiety of phospholipids in these multicomponent systems will be useful to researchers carrying out molecular dynamic simulations of membrane motions by providing experimental tests of computational results.

高分辨率场循环核磁共振方法将被开发为研究模型膜中磷脂的动力学和头基方向的强大工具。初步工作将测试在数据缩减和初步 31P 研究解释中所做的假设。这将需要合成不同片段已被氘化的磷脂，以及将模型系统的场循环核磁共振数据与分子动力学模拟进行比较，以识别有助于弛豫率的双层运动。现场循环松弛结果还将与标准固定场 T1r 测量结果进行比较。一旦经过验证，现场循环方法将用于检查多组分囊泡和聚集体中的脂质头基构象和横向相互作用，以及与 Ca2+ 或胆固醇等添加剂的聚集体，表征两种外周蛋白（膜联蛋白 V 和色褐链霉菌磷脂酶 D）的特异性相互作用，这两种外周蛋白对给定的头基磷脂表现出动力学或结合特异性。 多组分囊泡，并评估跨膜螺旋肽 WALP16 对磷酸盐构象和动力学的影响。虽然对这些不同系统的检查应该对该方法的有用性进行严格评估，但结果本身将提供有关两种外周蛋白和跨膜螺旋如何影响多组分系统中磷脂磷酸部分的动力学和构象的详细信息。本科生和研究生都将接受核磁共振理论和实验的培训。在实验室与 PI 和合作者进行一对一的接触将有助于培养下一代研究人员和科学教育者。这项研究结果的传播将为 NMR 界介绍一种强大的新方法，该方法易于使用传统光谱仪实施，最适合表征不同的磷脂聚集体和磷脂/蛋白质相互作用。这些多组分系统中磷脂磷酸酯部分的动力学和构象的定量信息将有助于研究人员通过提供计算结果的实验​​测试来进行膜运动的分子动力学模拟。