Alcohol-induced conformational changes of ubiquitin.
Alcohol-induced conformational changes of ubiquitin.
复制标题
酒精诱导的泛素构象变化。
DOI：
10.1016/0003-9861(86)90741-1
复制
发表时间：
1986
影响因子：
3.9
通讯作者：
Mayer,AN
中科院分区：
文献类型：
--
作者：
Wilkinson,KD;Mayer,AN
泛素已被发现以高氯酸盐或盐酸盐的形式溶解于乙二醇和醇中。当考察酒精对泛素结构的影响时，观察到两个可逆的构象转变。当将泛素的乙醇水溶液的介电常数从80降低到45时，泛素的天然结构被转化为与50%螺旋结构一致的形式。这种构象变化导致泛素的单一蛋氨酸和单一酪氨酸残基暴露在溶剂中的变化。与结晶学结果一致，这些残基被埋在天然构象中，但在经历这种转变时完全暴露在溶剂中。介电常数进一步降低到20会导致几乎完全螺旋结构的构象的积累。因此，疏水相互作用导致泛素结构容易发生构象变化。用择优溶剂化模型对这些结果进行了讨论。结果表明，用介电常数标度可以对不同醇的测量结果进行归一化处理。这种归一化校正了不同醇的不同摩尔体积，允许比较不同醇的结果，对于研究不同蛋白质的这种现象应该是有用的。
Ubiquitin has been found to be soluble in ethylene glycol and alcohols as the perchlorate or hydrochloride salt. When the effect of alcohol on the structure of ubiquitin is examined, two reversible conformational transitions are observed. Upon lowering the dielectric constant of aqueous alcohol solutions of ubiquitin from 80 to 45, the native structure of ubiquitin is converted to a form consistent with 50% helical structure. This conformational change results in a change in exposure to solvent of the single methionine and the single tyrosine residues of ubiquitin. In agreement with crystallographic results, these residues are buried in the native conformation but become fully exposed to solvent upon undergoing this transition. Further lowering of the dielectric constant to 20 results in the accumulation of a conformation with almost complete helical structure. Thus, hydrophobic interactions cause facile conformational changes in the ubiquitin structure. These results are discussed in terms of a preferential solvation model. It is shown that the results obtained with different alcohols can be normalized by the use of a dielectric constant scale. This normalization corrects for the different molar volumes of different alcohols, allows comparison of results obtained with different alcohols, and should be useful in studying this phenomenon with different proteins.