The effects of cation adduction upon the conformation of three-helix bundle protein domains
The effects of cation adduction upon the conformation of three-helix bundle protein domains
复制标题
阳离子加合对三螺旋束蛋白结构域构象的影响
DOI：
10.1007/s12127-012-0114-0
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发表时间：
2012
影响因子：
--
通讯作者：
Sokratous K
中科院分区：
文献类型：
--
作者：
Sokratous K
泛素结合，三螺旋束结构域的蛋白ubiquilin 1（UQ 1）和hHR 23 A都表现出显着的高，但离散，铵离子加合时，从含水醋酸铵电喷雾。加合程度高度依赖于电荷状态，不寻常的是，最低电荷状态（对于UQ 1为+3，对于hHR 23 A为+4）显示几乎没有加合物，而最高电荷状态（对于UQ 1为+5，对于hHR 23 A为+6）显示与两种铵阳离子的加合作为最丰富的形式。由于电喷雾电离（ESI）产生的蛋白质离子的电荷状态与溶剂可及的表面积有关，我们推断携带铵的离子比它们的质子化对应物具有更开放的构象。这是证实了ESI-行波离子迁移谱-质谱（TWIMS-MS），这表明，虽然纯质子化的离子是紧凑的，他们的等价物轴承一个或两个铵加合物表现出人口显着更大的碰撞截面（CCS）。我们假设与铵阳离子的络合可能会破坏紧凑结构中的关键盐桥。在单钠离子加合中观察到类似的效果，但这随着络合物中每增加一个钠离子而减少，以产生更紧凑的结构。
The ubiquitin-binding, three-helix bundle domains of the proteins ubiquilin 1 (UQ1) and hHR23A both exhibited remarkably high, but discrete, ammonium ion adduction when electrosprayed from aqueous ammonium acetate. The degree of adduction was highly charge state dependent with, unusually, the lowest charge states (+3 for UQ1 and +4 for hHR23A) showing almost no adducts and the highest charge states (+5 for UQ1 and +6 for hHR23A) exhibiting adduction with two ammonium cations as the most abundant form. As the charge state of protein ions produced by electrospray ionisation (ESI) is related to solvent-accessible surface area we inferred that the ammonium-carrying ions were of a more open conformation than their protonated counterparts. This was confirmed by ESI-travelling wave ion mobility spectrometry-mass spectrometry (TWIMS-MS), which showed that, although the purely protonated ions were compact, their equivalents bearing one or two ammonium adducts exhibited populations of significantly larger collisional cross section (CCS). We postulate that complexation with the ammonium cation may disrupt a key salt bridge(s) in the compact structure. A similar effect is observed with mono-sodium ion adduction, but this is diminished with each additional sodium ion in the complex to produce more compact structures.
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影响因子：
7.4
作者：
Dwivedi, Prabha;Wu, Ching;Hill, Herbert H., Jr.
通讯作者：
Hill, Herbert H., Jr.
影响因子：
16.6
作者：
Jenner, Matthew;Ellis, Jacqueline;Oldham, Neil J.
通讯作者：
Oldham, Neil J.
使用离子淌度质谱和碰撞截面算法研究有机金属钌抗癌复合物及其与 DNA 寡核苷酸的加合物。
DOI：
10.1002/rcm.4285
发表时间：
2009
期刊：
Rapid communications in mass spectrometry : RCM
影响因子：
--
作者：
Jonathan P. Williams;Julie Ann Lough;I. Campuzano;K. Richardson;P. Sadler
通讯作者：
P. Sadler
影响因子：
1.8
作者：
Felitsyn, N;Peschke, M;Kebarle, P
通讯作者：
Kebarle, P
影响因子：
15
作者：
van Duijn, Esther;Barendregt, Arjan;Heck, Albert J. R.
通讯作者：
Heck, Albert J. R.