NMR AND DATA REDUCTION TECHNIQUES FOR LARGE BIOMOLECULES

我们计划开发用于结构研究的核磁共振和计算方法 大的蛋白质。这将包括进一步发展多维 构象无关序列的多重共振技术 同核和异核偶联的归属和测量 常量。这可能导致更好地表征二面角， 侧链取向和多肽平面的取向。这将是 提高识别氢键的可能性，并可能导致 更高质量的大蛋白质结构。这些技术需要 谐振位置的精确测量。因此，我们提出质子 解耦方案将提高分辨率和敏感度 异核多维核磁共振波谱。此外，我们还将 广泛探索处理截断数据集的方法，检查和 应用非线性采样技术并开发处理软件 可以处理这样的数据集。要利用提高的分辨率，请使用大型 将不得不处理多维数据集。目前，这是 由于计算速度和磁盘空间的限制，实现起来非常困难。 因此，我们处于一个高分辨率和高分辨率的情况下 使用先进的核磁共振技术可获得的信息内容必须 由于计算设施的限制而牺牲。我们 因此建议购买一台大数据量的快速并行计算机 存储设备以及移植/开发核磁共振处理、分析和其他 相关软件。分析多维核磁共振波谱需要 通过3D或4D光谱的2D交叉面进行广泛的分页。我们计划 开发一种掩模卷积技术，将导致快速和稳健的 交叉峰的指认。随之而来的是 多维核磁共振谱中的自动指配技术。最后， 为了指导测量结构参数的工作，我们将 执行模拟以估计精确确定以下各项的影响 同核和异核邻位偶合常数相对于和In 此外，还可以精确而全面地测量交叉松弛速率。至 改进后一个方面，我们将适应并进一步开发一个迭代 Koehl和Lefevre(1990)提出的直接分离策略 交叉弛豫和自旋扩散。

We plan to develop NMR and computational methods for structural studies of large proteins. This will include further development of multidimensional multiple resonance techniques for conformation-independent sequential assignments and for measurements of homonuclear and heteronuclear coupling constants. This may lead to a better characterization of dihedral angles, side chain orientations and orientations of the peptide planes. This will improve the possibility of identifying hydrogen bonds and may lead to higher quality structures of large proteins. These techniques require precise measurements of resonance positions. We therefore propose proton decoupling schemes that will increase resolution and sensitivity in heteronuclear multidimensional NMR spectra. Furthermore, we will extensively explore methods of processing truncated data sets, examine and apply non-linear sampling techniques and develop processing software that can handle such data sets. To make use of the increased resolution, large multidimensional data sets will have to be handled. At present, this is extremely difficult due to limitations of computing speed and disk space. Consequently, we are in a situation where high resolution and high information content obtainable with advanced NMR technology must be sacrificed due to limitations of the computational facilities. We therefore propose to purchase a fast parallel computer with a large data storage device and to port/develop NMR processing, analysis and other related software. Analysis of multidimensional NMR spectra requires extensive paging through 2D cross planes of 3D or 4D spectra. We plan to develop a mask convolution technique that will lead to a quick and robust assignment of cross peaks. This will be accompanied by development of automated assignment techniques in multidimensional NMR spectra. Finally, to direct the effort in measurements of structural parameters, we will perform simulations to estimate the impact of precise determination of homonuclear and heteronuclear vicinal coupling constants relative to and in addition to measuring cross relaxation rates precisely and in large. To improve the latter aspect we will adapt and further develop an iterative strategy proposed by Koehl and Lefevre (1990) for the separation of direct cross relaxation and spin diffusion.