Solid-State NMR Derived Structure: Membrane-Bound Polypetides to Protein

固态 NMR 衍生结构：膜结合的多肽与蛋白质

• 批准号: 9603935
• 负责人: Timothy Cross
• 金额: $ 36万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-02-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9603935&HistoricalAwards=false
• 关键词: Solid; State; NMR; Derived; Structure

9603935 Cross The knowledge gained from the gramicidin studies will now be used to face the challenges associated with a biosynthetically prepared protein, M2 protein, studied as a dilute species in a lipid bilayer. Improvements in sensitivity will come from modications in the sample geometry, increased field strength and improvements in the experimental protocols. Linewidths in the M2 samples are primarily dominated by sample heterogeneity which through adjustments in sample preparation techniques can be addressed and there is also reasonable expectations that linewidths (in ppm) at least in some cases will decrease the increasing field strength. The mathematical challenges will involve the characterization of imperfect alpha-helices that are prevalent in membrane proteins. The work will take this solid state NMR method that utilizes orientational rather than distance constraints and apply it to a "real" protein system. High technology methods involving Nuclear Magnetic resonance (NMR) spectroscopy will be developed to solve the three-dimensional structures of macromolecules. Typically such structures are determined by diffraction methods applied to crystallized samples, but there are many important macromolecules that are not crystallizable. This unique NMR approach uses samples that are uniformly aligned, in other words they are oriented in one dimension, while crystals involve three-dimensional order. The molecular system that will be used for demonstrating these methods is protein that forms an ion channel in membranes. The NMR data obtained will be analyzed by new mathematical approaches that will be generally applicable to many molecular systems. Overall, the development of this structure determination approach will open new avenues of research for a great many types of molecules that are not easily crystallized. The work will provide great training opportunities for graduate students and postdocs in an interdisciplinary environment where molecular biology, synthetic chemistr y, NMR spectroscopy, NMR hardware development, molecular modeling and mathematical analysis occur in the confines of this research effort.

9603935 Cross 从短杆菌肽研究中获得的知识现在将用于应对与生物合成制备的蛋白质 M2 蛋白质相关的挑战，该蛋白质作为脂质双层中的稀释物质进行研究。灵敏度的提高将来自样品几何形状的修改、场强的增加和实验方案的改进。 M2 样品中的线宽主要由样品异质性决定，可以通过调整样品制备技术来解决这一问题，并且还合理地预期线宽（以 ppm 为单位）至少在某些情况下会降低场强的增加。 数学挑战将涉及膜蛋白中普遍存在的不完美α螺旋的表征。 这项工作将采用这种利用方向而不是距离限制的固态核磁共振方法，并将其应用于“真正的”蛋白质系统。 将开发涉及核磁共振（NMR）光谱的高科技方法来解析大分子的三维结构。 通常，这种结构是通过应用于结晶样品的衍射方法来确定的，但有许多重要的大分子是不可结晶的。 这种独特的核磁共振方法使用均匀排列的样品，换句话说，它们在一维上取向，而晶体则涉及三维顺序。 将用于演示这些方法的分子系统是在膜中形成离子通道的蛋白质。 获得的核磁共振数据将通过新的数学方法进行分析，这些方法通常适用于许多分子系统。 总的来说，这种结构测定方法的发展将为许多类型的不易结晶的分子开辟新的研究途径。 这项工作将为研究生和博士后在跨学科环境中提供良好的培训机会，其中分子生物学、合成化学、核磁共振波谱、核磁共振硬件开发、分子建模和数学分析都发生在这项研究工作的范围内。