Bovine serum albumin and aqueous guanidine hydrochloride solutions. Preferential and absolute interactions and comparison with other systems.
Bovine serum albumin and aqueous guanidine hydrochloride solutions. Preferential and absolute interactions and comparison with other systems.
复制标题
牛血清白蛋白和盐酸胍水溶液。
DOI：
10.1021/bi00621a006
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发表时间：
1977
期刊：
影响因子：
2.9
通讯作者：
H. Eisenberg
中科院分区：
文献类型：
--
作者：
E. Reisler;Y. Haik;H. Eisenberg
在盐酸胍 (GuHC1)、0.01 M 二硫赤藓糖醇 (DTE) 溶液中，25°C 时牛血清白蛋白的部分比容 upsilon20 为 0.728 +/- 0.001 ml/g，与 GuHC1 浓度 (3-6 M) 无关。变性时体积减少约400ml/mol（相同温度下在水中的upsilon20为0.734）。根据可扩散溶质在恒定化学势下减少的密度增量，发现表观体积 phi 从 3 M GuHCl 下的 0.693 ml/g 增加到 7 M GuHCl 下的约 0.725 ml/g。现象学相互作用参数 xi3（每克蛋白质“结合”的 GuHC1 克数）被发现从 3 M GuHC1 时的约 0.2 减少到 6.4 M GuHC1 时的约 0.07。现象学相互作用参数 xi1（每克蛋白质“结合”的水克数）为负值，并且随着 GuHC1 浓度的增加，负值变得越来越小。 xi3 和xi1 之间的关系以及低分子量组分的物理结合和排除从简单模型的角度进行了讨论。结论是，在研究的 GuHC1 浓度范围内，每克蛋白质结合约 0.2 g 水和 0.28 g GuHC1。这平均相当于每个氨基酸残基 1.3 个水分子和 0.35 个 GuHC1 分子。通过重新计算醛缩酶的一些先前结果，发现了类似的结果。 GuHC1 溶液中蛋白质的这些结果与在高浓度 NaCl 和 CsCl 下的 DNA 行为形成鲜明对比，后者是在早期工作的基础上进行分析的。
The partial specific volume, upsilon20, of bovine serum albumin at 25 degrees C was found to be 0.728 +/- 0.001 ml/g in solutions of guanidine hydrochloride (GuHC1), 0.01 M dithioerythritol (DTE), independent of GuHC1 concentration (3-6 M). The volume decrease upon denaturation is about 400 ml/mol (upsilon20 in water at the same temperature was found to be 0.734). From the reduced density increments at constant chemical potential of diffusible solutes, The apparent volumes, phi, were found to increase from 0.693 ml/g at 3 M GuHC1 to about 0.725 ml/g at 7 M GuHC1. The phenomenological interaction parameter, xi3 (grams of GuHC1 "bound" per gram of protein), was found to decrease from about 0.2 at 3 M GuHC1 to about 0.07 at 6.4 M GuHC1. The phenomenological interaction parameter, xi1 (grams of water "bound" per gram of protein), is negative and become less negative with increase in GuHC1 concentration. The relation between xi3 and xi1 and physical binding and exclusion of low-molecular-weight components are discussed in terms of simple model consideration. It is concluded that over the range of GuHC1 concentrations studied about 0.2 g of water as well as 0.28 g of GuHC1 are bound per gram of protein. This corresponds on the average to 1.3 molecules of water and 0.35 molecule of GuHC1 per amino acid residue. Similar results were found by recalculating some previous results for aldolase. These results on proteins in GuHC1 solution are in marked contrast to the behavior of DNA at high concentrations of NaCl and CsCl, which is analyzed on the basis of earlier work.