Charge density-dependent modifications of hydration shell waters by Hofmeister ions.
Charge density-dependent modifications of hydration shell waters by Hofmeister ions.
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Hofmeister离子对水合壳水的电荷密度依赖性修饰。
DOI：
10.1021/ja902240j
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发表时间：
2009-08-12
影响因子：
15
通讯作者：
Friedman JM
中科院分区：
文献类型：
--
作者：
Guo F;Friedman JM
Gd3+(Gd3+)振动边带发光光谱(GVSBLS)被用来探测作为添加Hofmeister系列盐的函数的Gd3+水溶液和Gd3+与三种不同类型的分子配位的第一壳层水产生的OH伸展频率的变化：i)螯合物(EDTA)，ii)具有单一高亲和力结合位点的稀土结合标签(LBTS)家族的结构多肽(mSE3/SE2)；以及iii)具有四个结合位点的钙结合蛋白(钙调素)。当Gd3+与EDTA、钙调蛋白或mSE3多肽配位时，与Gd3+配位的水的OH伸缩模式对应的振动边带(VSB)的频率与与邻近水域的氢键强度成反比。在所有这些情况下，阳离子氯化物或醋酸盐的加入都以阳离子和浓度依赖的方式增加了源于配位水的OH伸展模式的振动带的频率。频率增加对阳离子的依赖程度与阳离子的电荷密度成比例关系，从而产生与Hofmeister有序一致的有序性。另一方面，水的拉曼光谱在加入这些盐后没有显着的变化。此外，还发现阳离子效应受特定阴离子的调制。结果表明，Hofmeister系列离子的作用机理是水化壳层水之间的氢键受多种因素的影响。高电荷密度的阳离子以一种阻止与邻近水域形成强氢键的构型隔离水。在这种情况下，当阴离子与水化壳表面的剩余自由水竞争氢键位置时，就会出现负离子效应。阴离子效应的大小与阳离子和Gd3+结合部位有关。
Gadolinium (Gd3+) vibronic side band luminescence spectroscopy (GVSBLS) is used to probe, as a function of added Hofmeister series salts, changes in the OH stretching frequency derived from first shell waters of aqueous Gd3+ and of Gd3+ coordinated to three different types of molecules: i) a chelate (EDTA), ii) structured peptides (mSE3/SE2) of the lanthanide-binding tags (LBTs) family with a single high affinity binding site; and iii) a calcium binding protein (calmodulin) with four binding sites. The vibronic side band (VSB) corresponding to the OH stretching mode of waters coordinated to Gd3+, whose frequency is inversely correlated with the strength of the hydrogen bonding to neighboring waters, exhibits an increase in frequency when Gd3+ becomes coordinated to either EDTA, calmodulin or mSE3 peptide. In all of these cases, the addition of cation chloride or acetate salts to the solution increases the frequency of the vibronic band originating from the OH stretching mode of the coordinated waters in a cation and concentration-dependent fashion. The cation dependence of the frequency increase scales with charge density of the cations giving rise to an ordering consistent with the Hofmeister ordering. On the other hand water Raman shows no significant change upon addition of these salts. Additionally, it is shown that the cation effect is modulated by the specific anion used. The results indicate a mechanism of action for Hofmeister series ions in which hydrogen bonding among hydration shell waters is modulated by several factors. High charge density cations sequester waters in a configuration that precludes strong hydrogen bonding to neighboring waters. Under such conditions anion effects emerge as anions compete for hydrogen bonding sites with the remaining free waters on the surface of the hydration shell. The magnitude of the anion effect is both cation and Gd3+-binding site specific.
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影响因子：
56.9
作者：
AUSTIN, RH;BEESON, K;MARSHALL, VP
通讯作者：
MARSHALL, VP
影响因子：
3.3
作者：
Chalikian, TV
通讯作者：
Chalikian, TV
DOI：
10.1073/pnas.212637899
发表时间：
2002-12-10
影响因子：
11.1
作者：
Fenimore, PW;Frauenfelder, H;Parak, FG
通讯作者：
Parak, FG
DOI：
10.1073/pnas.87.1.1
发表时间：
1990-01-01
影响因子：
11.1
作者：
BERENDZEN, J;BRAUNSTEIN, D
通讯作者：
BRAUNSTEIN, D
影响因子：
4.4
作者：
Cho, CH;Urquidi, J;Robinson, GW
通讯作者：
Robinson, GW