Protective Effects of Dimethyl Sulfoxide on Labile Protein Interactions during Electrospray Ionization
Protective Effects of Dimethyl Sulfoxide on Labile Protein Interactions during Electrospray Ionization
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DOI：
10.1021/ac500879c
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发表时间：
2014-05-06
影响因子：
7.4
通讯作者：
Jornvall, Hans
中科院分区：
文献类型：
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作者：
Landreh, Michael;Alvelius, Gunvor;Jornvall, Hans
电喷雾离子化质谱是探测非共价相互作用的有价值的工具。然而，气相中相互作用的完整性受到电离过程的严重影响。研究甲状腺素运载蛋白（TTR）和前表面活性蛋白C的伴侣结构域的寡聚化和配体结合，我们发现二甲基亚砜（DMSO）可以提高电喷雾过程中的非共价相互作用的稳定性，无论是关于配体结合还是蛋白质四级结构。即使在不稳定条件下，少量DMSO也可以减少天然蛋白质寡聚体的源内解离及其与疏水配体的相互作用。我们解释DMSO的效果是来自其富集在蒸发过程中的电喷雾液滴。保护不稳定的相互作用可以从离子电荷的减少来减少库仑排斥的贡献，以及从加合物解离的冷却效应。DMSO对不稳定蛋白质相互作用的保护作用是一个重要的性质，因为它广泛用于电喷雾电离质谱（ESI-MS）的蛋白质分析。
Electrospray ionization mass spectrometry is a valuable tool to probe noncovalent interactions. However, the integrity of the interactions in the gas-phase is heavily influenced by the ionization process. Investigating oligomerization and ligand binding of transthyretin (TTR) and the chaperone domain from prosurfactant protein C, we found that dimethyl sulfoxide (DMSO) can improve the stability of the noncovalent interactions during the electrospray process, both regarding ligand binding and the protein quaternary structure. Low amounts of DMSO can reduce in-source dissociation of native protein oligomers and their interactions with hydrophobic ligands, even under destabilizing conditions. We interpret the effects of DMSO as being derived from its enrichment in the electrospray droplets during evaporation. Protection of labile interactions can arise from the decrease in ion charges to reduce the contributions from Coulomb repulsions, as well as from the cooling effect of adduct dissociation. The protective effects of DMSO on labile protein interactions are an important property given its widespread use in protein analysis by electrospray ionization mass spectrometry (ESI-MS).