Effects of supercharging reagents on noncovalent complex structure in electrospray ionization from aqueous solutions.
Effects of supercharging reagents on noncovalent complex structure in electrospray ionization from aqueous solutions.
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DOI：
10.1016/j.jasms.2010.06.012
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发表时间：
2010-10
影响因子：
3.2
通讯作者：
Williams ER
中科院分区：
文献类型：
--
作者：
Sterling HJ;Daly MP;Feld GK;Thoren KL;Kintzer AF;Krantz BA;Williams ER
研究了两种增压剂间硝基苯甲醇（m-NBA）和环丁砜对肌红蛋白离子电喷雾电离形成的电荷态分布和构象的影响。与不含m-NBA的溶液相比，向肌红蛋白的乙酸铵水溶液中添加0.4% m-NBA导致最大电荷状态从9+增加到19+，并且平均电荷状态从7.9+增加到11.7+。以每摩尔计，环丁砜的增压程度低于m-NBA，但在较高浓度下获得了相当的充电。从行波离子迁移谱法获得的到达时间分布表明，与这些增压试剂形成的较高电荷态离子比较低电荷态离子明显更多地展开。圆二色光谱的结果表明，环丁砜可以作为化学变性剂，在25 °C下使肌红蛋白不稳定约1.5 kcal/mol/M。因为这些增压试剂具有低蒸气压，所以随着蒸发发生，水性液滴优先富集这些试剂。在液滴基本上富含低挥发性增压试剂之后将发生较少的蒸发冷却，并且与不存在这些试剂时相比，液滴温度应该更高。由化学和/或热变性诱导的蛋白质展开似乎是观察到的非共价蛋白质复合物形成的水溶液，含有这些增压试剂的增强充电的主要来源，虽然其他因素几乎肯定会影响充电的程度以及。
The effects of two supercharging reagents, m-nitrobenzyl alcohol (m-NBA) and sulfolane, on the charge-state distributions and conformations of myoglobin ions formed by electrospray ionization were investigated. Addition of 0.4% m-NBA to aqueous ammonium acetate solutions of myoglobin results in an increase in the maximum charge state from 9+ to 19+, and an increase in the average charge state from 7.9+ to 11.7+, compared to solutions without m-NBA. The extent of supercharging with sulfolane on a per mole basis is lower than that with m-NBA, but comparable charging was obtained at higher concentration. Arrival time distributions obtained from traveling wave ion mobility spectrometry show that the higher charge state ions that are formed with these supercharging reagents are significantly more unfolded than lower charge state ions. Results from circular dichroism spectroscopy show that sulfolane can act as chemical denaturant, destabilizing myoglobin by ~1.5 kcal/mol/M at 25 °C. Because these supercharging reagents have low vapor pressures, aqueous droplets are preferentially enriched in these reagents as evaporation occurs. Less evaporative cooling will occur after the droplets are substantially enriched in the low volatility supercharging reagent, and the droplet temperature should be higher compared to when these reagents are not present. Protein unfolding induced by chemical and/or thermal denaturation appears to be the primary origin of the enhanced charging observed for noncovalent protein complexes formed from aqueous solutions that contain these supercharging reagents, although other factors almost certainly influence the extent of charging as well.
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影响因子：
2.8
作者：
Davies, NW;Wiese, MD;Browne, SGA
通讯作者：
Browne, SGA
影响因子：
15
作者：
BRUCE, JE;CHENG, X;SMITH, RD
通讯作者：
SMITH, RD
影响因子：
3.1
作者：
Abbruzzetti, Stefania;Sottini, Silvia;Corrie, John E. T.
通讯作者：
Corrie, John E. T.
影响因子：
7.4
作者：
Charlebois, JP;Patrie, SM;Kelleher, NL
通讯作者：
Kelleher, NL
影响因子：
3.8
作者：
GIACOMETTI, GM;ANTONINI, E;BRUNORI, M
通讯作者：
BRUNORI, M