Samuni Uri, Dantsker David, Roche Camille J, Friedman Joel M
Albert Einstein College of Medicine, Department of Physiology and Biophysics, Bronx, New York 10461, USA.
Gene. 2007 Aug 15;398(1-2):234-48. doi: 10.1016/j.gene.2007.04.032. Epub 2007 May 10.
Ligand recombination studies play a central role both for characterizing different hemeproteins and their conformational states but also for probing fundamental biophysical processes. Consequently, there is great importance to providing a foundation from which one can understand the physical processes that give rise to and modulate the large range of kinetic patterns associated with ligand recombination in myoglobins and hemoglobins. In this work, an overview of cryogenic and solution phase recombination phenomena for COMb is first reviewed and then a new paradigm is presented for analyzing the temperature and viscosity dependent features of kinetic traces in terms of multiple phases that reflect which tier(s) of solvent slaved protein dynamics is (are) operative on the photoproduct population during the time course of the measurement. This approach allows for facile inclusion of both ligand diffusion among accessible cavities and conformational relaxation effects. The concepts are illustrated using kinetic traces and MEM populations derived from the CO recombination process for wild type and mutant myoglobins either in sol-gel matrices bathed in glycerol or in trehalose-derived glassy matrices.
配体重组研究对于表征不同的血红素蛋白及其构象状态以及探究基本的生物物理过程都起着核心作用。因此，提供一个基础至关重要，借此人们能够理解那些引发并调节与肌红蛋白和血红蛋白中配体重组相关的大范围动力学模式的物理过程。在这项工作中，首先回顾了COMb的低温和溶液相重组现象的概述，然后提出了一种新的范式，用于根据反映在测量过程中光产物群体上起作用的溶剂从属蛋白质动力学的哪一层（或几层）的多相来分析动力学轨迹的温度和粘度依赖性特征。这种方法便于同时纳入可及腔之间的配体扩散和构象弛豫效应。使用从野生型和突变型肌红蛋白在甘油浴中的溶胶 - 凝胶基质或海藻糖衍生的玻璃基质中的CO重组过程获得的动力学轨迹和最大熵方法（MEM）群体来说明这些概念。
