THEORETICAL STUDIES ON THE DYNAMIC ASPECTS OF MACROMOLECULAR FUNCTION

烃链的布朗动力学模拟结果 在一个膜双层被用来分析NMR弛豫 实验，以产生有关动力学的信息， 囊泡中类脂质的排列。 结果表明，频率 数据的依赖性不产生于trans-gauche 异构化或整个分子的轴向旋转。 定量协议是使用一个模型，其中快速轴向 旋转（约100 ps）和大振幅（具有顺序 参数约0.6），但缓慢的指向矢波动 （大约10 ns）叠加在内部运动上。 这项工作支持了一个非常流畅的画面内部的 与普遍接受的模型相反， 曲轴运动占主导地位。 利用随机理论， 化学反应和首次通过时间理论，一个简单的 导出了延迟时间分布的解析表达式 这在聚合动力学研究中已经观察到 镰状血红蛋白的聚合反应 进展曲线表现出随机变化。 率 均匀成核可以容易地从这种 使用这个表达式的实验。 这项工作构成了 这是对相当有限的例子的重要补充， 联系可以成功地作出之间的随机理论， 化学动力学与实验 内部的影响 电子转移反应中的构象动力学 检测供体和受体。 稳定凝视通量 两个多态系统耦合产生的结果被证明， 与从简单动力学方案计算的结果相同 只涉及四个状态，如果有效速率常数， 约化方案是近似定义的平均第一 在沿着的各个点之间移动的通过时间 多状态循环

The results of a Brownian dynamics simulation of hydrocarbon chain in a membrane bilayer were used to analyze NMR relaxation experiments to yield information concerning the dynamics and ordering of lioids in vesicles. It was shown that the frequency dependence of the data does not arise from trans-gauche isomerizations or from axial rotation of the entire molecule. Quantative agreement is found using a model in which fast axial rotations (approximately 100ps) and large amplitude (with order parameter approximately 0.6) but slow director fluctuations (approximately 10ns) are superimposed on the internal motions. This work supports a very fluid picture of the interior of the bilayer in contrast to the commonly accepted model in which crankshaft motions predominate. Using the stochastic theory of chemical reactions and the theory of first passage times, a simple analytic expression is derived for the distribution of delay times that has been observed in studies of the polymerization kinetics of sickle hemoglobin under conditions where the polymerization progress curves exhibit stochastic variation. The rate of homogeneous nucleation can be readily extracted from such experiments using this expression. This work constitutes a significant addition to the rather limited number of examples where contact can be successfully made between the stochastic theory of chemical kinetics and experiment. The influence of internal conformational dynamics in the electron transfer reaction between a donor and an acceptor was examined. The steady stare flux resulting from the coupling of two multistate systems was shown to be identical to that calculated from a simple kinetic scheme involving only four states, if the effective rate constants of this reduced scheme are approximately defined in terms of the mean first passage times for moving between various points along the multistate cycles.