论文标题
盐诱导的中间体在球状蛋白分散液的液态液相转变中的可能作用
A possible role of salt-induced intermediates in the liquid-liquid phase transitions of globular protein dispersions
论文作者
论文摘要
已经提出了在热（D*）和冷（D*）之间温度范围内的天然（N*，N）球状蛋白水盐分散体中液态液（L-L）类型相变的可能模型。在d <-> n和d* <-> n*的过程中，由于离子非平衡（DE）吸附引起的蛋白质中间体（I，I*）被认为与N和N*蛋白质的内相中的L-L微相变形形成簇和原纤维有关。因此，与N蛋白相比，它们补偿了由于吸附盐离子在蛋白质结构中吸附的盐离子不平衡分布引起的过量化学潜力（CHPOT）。提出了一个温度模型，以实现蛋白质各种状态的CHPOTS（Delta Mui）的行为：低温i = D，N，I和高温i = D*，N*，I*以及它们之间的过渡。在此基础上，提出了溶剂CHPOT DELTA MU1的温度依赖性。建立了L-L转变的临界点（上和下部临界溶液温度）的极端值与临界点（上下临界溶液温度）之间的关系。根据相图讨论了在水盐蛋白分散体中不同温度下渗透压的非理想行为的原因。
A probable model of the liquid-liquid (L-L) type phase transitions in water-salt dispersions of native (N*, N) globular proteins in the temperature range between thermal (D*) and cold (D) denaturation has been proposed. Protein intermediates (I, I*) arising as a result of the ion non-equilibrium (de)sorption in the process of D <-> N and D* <-> N* transitions are assumed to be involved in the L-L micro-phase transition forming clusters and fibrils in the main phase of N and N* proteins. Thus, they compensate for their excess chemical potential (ChPot) caused by unbalanced distribution of adsorbed salt ions in protein structure as compared to N-protein. A temperature model is proposed for the behavior of ChPots (delta mui) of various states of the protein: low-temperature i = D, N, I and high-temperature i = D*, N*, I*, as well as the transition between them. On this basis, the temperature dependence of the solvent ChPot delta mu1 is proposed. The relationship between the extreme values of delta mu1 and the temperatures of the critical points (upper and lower critical solution temperatures) of L-L transitions is established. The reasons for the nonideal behavior of osmotic pressure at different temperatures in water-salt protein dispersions are discussed on the basis of the phase diagrams.
