Interactions of proteins with solvent components in 8 M urea.
Interactions of proteins with solvent components in 8 M urea.
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DOI：
10.1016/0003-9861(81)90209-5
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发表时间：
1981-09
影响因子：
3.9
通讯作者：
V. Prakash;C. Loucheux;Stephen Scheufele;M. J. Gorbunoff;S. N. Timasheff
中科院分区：
文献类型：
--
作者：
V. Prakash;C. Loucheux;Stephen Scheufele;M. J. Gorbunoff;S. N. Timasheff
通过测定分子量范围为9000至41，000的九种蛋白质在8 m尿素溶液中的表观部分比体积来研究蛋白质与尿素之间的相互作用。在等摩尔和等电位条件下测定了表观偏比容。与溶剂组分的优先相互作用，从所获得的值计算，在0和0.14克尿素每克蛋白质之间变化。在没有一种情况下是优先与水的相互作用。计算变性剂与每种蛋白质的总结合，并获得残基总数与每摩尔蛋白质结合的尿素摩尔数之间的相关性。针对与蛋白质结合的变性剂分子的观察到的和预期的数量，测试了几种模型。一个很好的相关性得到的模型，其中一个尿素分子被绑定到每对肽单元和一个到每个芳族侧链。与蛋白质的疏水性无关。将蛋白质从稀盐溶液转移到8 murea后的体积变化进行了计算;与文献中报道的各种变性剂的值进行比较，显示出良好的一致性。
The interaction between proteins and urea was investigated by determining the apparent partial specific volumes of nine proteins in the molecular weight range 9000 to 41,000 in 8murea solution. The apparent partial specific volumes were determined under both isomolal and isopotential conditions. The preferential interaction with solvent components, calculated from the obtained values, varied between zero and 0.14 g of urea per gram of protein. In none of the cases was the interaction preferential with water. The total binding of denaturant to each protein was calculated and the correlation between the total number of residues and the number of moles of urea bound per mole of protein was obtained. Several models were tested for the observed and expected number of denaturant molecules bound to the protein. A good correlation was obtained for the model in which one urea molecule was bound to each pair of peptide units and one to each aromatic side chain. There was no correlation whatever with protein hydrophobicity. The changes in volume upon transferring the proteins from dilute salt solution to 8murea were calculated; comparison with values reported in the literature for various denaturants showed good agreement.