SEMI-ANALYTIC APPROACHES TO SPIN RELAXATION IN PROTEINS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 电子自旋共振和核磁共振弛豫在蛋白质动力学研究中都被证明是有用的。我们率先采用了缓慢松弛局部结构(SRLS)的方法来解释它们。在这方面，它是非常成功的，特别是对于慢运动的ESR谱。在其目前相对方便的实现中，SRLS方法仍然需要计算；它们基于(过度抑制的)扩散运动的简化，并且是一种介观方法(与原子方法不同)。开展这一项目是为了改进战略最低限度办法。例如，蛋白质侧链在势垒中重新定向，将以扭转振荡的形式表现出惯性效应。此外，蛋白质的骨架动力学必然涉及集体动力学，以一种相对简单的方式，可以通过存在全局扩散的几个惯性线性旋转体的耦合来模拟集体动力学。另一个目标是获得极限分析模型，以减少在应用于ESR和核磁共振自旋弛豫时的计算挑战，并确定其有效性范围。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Both ESR and NMR relaxation have proved useful in the study of protein dynamics. We have pioneered the slowly-relaxing local structure (SRLS) approach to their interpretation. It has been very successful, especially for the slow-motional ESR spectra, in this regard. In its present, relatively convenient implementations, the SRLS approaches are still computationally demanding; they are based on the simplification of (overdamped) diffusive motions, and are a mesoscopic (as distinct from an atomic) approach. This project was undertaken to provide improvements on the SRLS approach. For example, a protein side-chain which reorients in a potential well, will exhibit inertial effects in the form of torsional oscillations. Also the backbone dynamics of a protein necessarily involves collective dynamics, which could, in a relatively simple manner, be modeled by the coupling of several inertial linear rotators in the presence of global diffusion. Another objective is to obtain limiting analytical models that reduce the computational challenges in application to ESR and NMR spin relaxation, and to determine their range of validity.