Combined charged residue-field emission model of macromolecular electrospray ionization.
Combined charged residue-field emission model of macromolecular electrospray ionization.
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DOI：
10.1021/ac8016532
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发表时间：
2009-01-01
影响因子：
7.4
通讯作者：
Gross, Michael L.
中科院分区：
文献类型：
--
作者：
Hogan, Christopher J., Jr.;Carroll, James A.;Rohrs, Henry W.;Biswas, Pratim;Gross, Michael L.
电喷雾离子化（ESI）中大分子多重带电的机理一直是人们争论的焦点。最近，我们提出，在一个大分子上的电荷的数量是由小的电荷载流子从含有大分子的纳米液滴的发射，并在溶剂蒸发后，剩余的电荷转移到大分子。在这项研究中，我们测试了这一新的理论的适用性，大分子，正离子ESI质谱测量的平均电荷状态和非变性和变性条件下的球状蛋白质的电荷分布。天然状态蛋白质的蛋白质平均电荷状态的预测与质谱测量结果非常一致，给所提出的理论提供了强有力的证据。理论预测也在良好的协议与平均电荷状态测量蛋白质在碱性溶液（pH = 11.5）。对于某些蛋白质在酸性溶液中（pH = 2.1），测得的平均电荷状态是令人不安的高于瑞利极限的水滴与体积相当于的蛋白质。我们建议，一些高电荷的大分子在溶液中可能会解吸从带电的液滴相同极性的电荷载体发射从纳米液滴，从而导致“增压”的大分子离子以类似的方式。溶剂蒸发和电荷载流子发射的速率表达式的检查表明，新提出的模型ESI与以前报道的离子发射动力学是一致的。总的来说，我们获得了额外的实验证据的电荷载流子发射模型的大分子充电，这表明理解和应用ESI-MS的机会。
The mechanism of the multiple charging of macromolecules in electrospray ionization (ESI) continues to inspire debate and controversy. Recently, we proposed that the number of charges on a macromolecule is determined by the emission of small charge carriers from macromolecule-containing nanodroplets and that, after solvent evaporation, the remaining charge is transferred to the macromolecule. In this study, we tested the applicability of this new theory for macromolecular, positive-ion ESI mass spectrometry by measuring the mean charge states and charge distributions of globular proteins under non-denaturing and denaturing conditions. Predictions of protein mean charge states for native state proteins are in excellent agreement with mass spectrometric measurements, giving strong credence to the proposed theory. Theoretical predictions are also in good agreement with mean charge states measured for proteins in basic solutions (pH = 11.5). For some proteins in acidic solutions (pH = 2.1), the measured mean charge states are anomalously higher than the Rayleigh limit of a water droplet with a volume equivalent to that of the protein. We propose that some macromolecules that are highly charged in solution may desorb from charged droplets of the same polarity in a similar manner to that whereby charge carriers emit from nanodroplets, leading to “supercharged” macromolecular ions. Examination of rate expressions for solvent evaporation and charge-carrier emission demonstrates that the newly proposed model for ESI is consistent with previously reported ion-emission kinetics. Overall, we obtained additional experimental evidence for the charge carrier emission model for macromolecular charging, suggesting opportunities for understanding and applying ESI-MS.
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DOI：
10.1016/j.jasms.2005.01.019
发表时间：
2005-05-01
影响因子：
3.2
作者：
de la Mora, JF;Thomson, BA;Gamero-Castaño, M
通讯作者：
Gamero-Castaño, M
影响因子：
1.8
作者：
Felitsyn, N;Peschke, M;Kebarle, P
通讯作者：
Kebarle, P
DOI：
10.1073/pnas.93.7.3143
发表时间：
1996-04-02
影响因子：
11.1
作者：
Gross, DS;Schnier, PD;Williams, ER
通讯作者：
Williams, ER
影响因子：
2.3
作者：
Bacher, G;Szymanski, WW;Allmaier, G
通讯作者：
Allmaier, G
影响因子：
7.4
作者：
Bakhoum, SFW;Bogan, MJ;Agnes, GR
通讯作者：
Agnes, GR