2D NMR STUDIES OF STRUCTURE & DYNAMICS OF CYTOCHROME C

在先前的工作中，使用二维质子核磁共振方法来确认， 修正或指定从头算起的血红素和一半以上的质子共振 马铁细胞色素c中的氨基酸。还有一些残留物 在其他细胞色素中被分配。c.这些的完整分配 相关的蛋白质将为研究提供无与伦比的资源。 蛋白质的结构和动力学。这也将提供一种特殊的 用于测试和使用新兴核磁共振技术的系统。初步结果 表明早些时候被认为对 将这些方法应用于较大的蛋白质(例如，自旋扩散， T1和T2效应)实际上不是问题。因此，我们建议 应用这些已被证明成功的分配策略来完成 马酵素的分配。在这里的成功将为 细胞色素c铁种(五种)的快速进一步指认 被提出)和它们的氧化对应物。将使用核磁共振技术 确定局部二级结构和动力学及其影响 氧化还原状态的变化和氨基酸的替代。结构将是 由NOE和耦合常数的时间依赖关系确定。 覆盖亚纳秒到秒的结构动力学 将会被研究。大部分的运动信息将从 NOESY实验中的驰豫数据和化学交换效应。 总体而言，这些结果有望为以下方面提供有趣的见解 蛋白质结构-功能关系及蛋白质结构 动力学。

In prior work two dimensional proton NMR methods were used to confirm, correct, or assign de novo the proton resonances of the heme and over half the amino acids in horse ferrocytochrome c. Also a number of residues have been assigned in other cytochromes c. A complete assignment of these related proteins would provide an unparalleled resource for studies of protein structure and dynamics. This would also provide an exceptional system for testing and using emerging NMR techniques. Preliminary results indicate that several effects earlier thought to pose serious barriers to the application of these methods to larger proteins (e.g. spin diffusion, T1 and T2 effects) are in fact not a problem. We therefore propose to apply these assignment strategies, already proven successful, to complete the assignment of the horse enzyme. Success here will provide the key to the rapid further assignment of additional ferrocytochrome c species (five are proposed) and their oxidized counterparts. NMR techniques will be used to define local secondary structure and dynamics and the effects thereon of change in redox state and amino acid substitution. Structure will be determined from the time dependence of the NOE and coupling constants. Structural dyamics covering the range between subnanoseconds and seconds will be studied. The majority of motional information will be derived from relaxation data and chemical exchange effects in the NOESY experiment. Overall these results are expected to provide interesting insights into protein structure-function relationships as well as protein structural dynamics.