Reversal of the Hofmeister Series: Specific Ion Effects on Peptides
Reversal of the Hofmeister Series: Specific Ion Effects on Peptides
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DOI：
10.1021/jp405683s
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发表时间：
2013-07-11
影响因子：
3.3
通讯作者：
Jungwirth, Pavel
中科院分区：
文献类型：
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作者：
Paterova, Jana;Rembert, Kelvin B.;Jungwirth, Pavel
离子特异性效应对于蛋白质的盐入和盐出、蛋白质变性以及酶活性通常可以根据霍夫迈斯特理论进行合理化。在这里，我们通过核磁共振光谱和分子动力学模拟证明，传统的霍夫迈斯特解释是不充分的。根据离子的整体水合性质对离子的排序。使用三甘氨酸作为模型系统，我们表明，Hofmeister系列的阴离子的变化，从一个直接到一个反向系列后，脱帽的N-末端。弱水合阴离子，如碘化物和硫氰酸根，与肽键相互作用;相反，在带正电荷的未封端的N-末端观察到阴离子的相互作用中的相反顺序，并且通过类推，在带正电荷的氨基的侧链上也应该是这种情况。这些结果表明，特定的化学和物理性质，肽和蛋白质的合成在离子特异性效应中起着重要作用。因此，本研究提供了阴离子的分子Hefmeister排序。它还提供了一种通过滴定或突变蛋白质表面上的碱性氨基酸残基来调节这些相互作用的途径。
Ion-specific effects On salting-in and salting-out of proteins, protein denaturation, as well as enzymatic activity are typically rationalized in terms of the Hofmeister Here, we demonstrate by means of NMR spectroscopy and, molecular dynamics simulations that the traditional explanation of the Hofmeister ordering of ions in term of their bulk hydration properties is inadequate. Using triglycine as a model system, we show that the Hofmeister series for anions changes from a direct to a reversed series upon uncapping the N- terminus. Weakly hydrated anions, such as iodide and thio cyanate, interact with the peptide bond; while strongly hydrated anions like sulfate are repelled from it. In Contrast reversed order in interactions, of anions is observed at the positively charged, uncapped N-terminus, and by analogy, this should also be the case at side chains of positively,Charged amino These results demonstrate that the specific chemical and physical properties, of peptides and proteins play a fundamental role in ion-specific effects.' The present study thus provides a molecular Hefmeister ordering for the anions. It also provides a route for tuning these interactions by titration or mutation of basic amino acid residues on the protein surface.