SELECTIVE BINDING AND SOLVENT DENATURATION
SELECTIVE BINDING AND SOLVENT DENATURATION
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DOI：
10.1002/bip.360260408
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发表时间：
1987-04-01
期刊：
影响因子：
2.9
通讯作者：
SCHELLMAN, JA
中科院分区：
文献类型：
--
作者：
SCHELLMAN, JA
溶剂变性的原始模型是变性剂独立地结合到通过蛋白质的解折叠而暴露的位点。对于像尿素和胍盐这样的试剂，这种结合必须非常弱，因为变性仅在非常高的浓度下发生。弱结合的标准公式导致热力学不一致。本文将变性剂的结合视为选择性溶剂化。这在结合等温线和结合自由能中引入了K - 1因子，其中K是与位点选择性相互作用的平衡常数。这导致结合和变性的化学上一致的描述，因为当K = 1时，没有选择性相互作用并且对变性没有影响，即使在位点占据是不可避免的浓缩溶液中。
A primitive model for solvent denaturation is that the denaturant binds independently to sites exposed by the unfolding of the protein. For reagents like urea and guanidinium salts, this binding must be very weak since denaturation occurs only at very high concentrations. Standard formulas for very weak binding lead to thermodynamic inconsistencies. In this paper, binding by denaturants is treated as selective solvation. This introduces a factor of K - 1 into the binding isotherm and binding free energy, where K is the equilibrium constant for selective interaction with the sites. This leads to a thermodynamically consistent description of the binding and the denaturation since, when K = 1, there is no selective interaction and no effect on denaturation, even in concentrated solutions where site occupancy is inevitable.