Detergents are commonly employed for solubilization and stabilization of integral membrane proteins. Their effects on the charge states of detergent-solubilized membrane proteins in native mass spectrometry measurements have previously been described. These effects can be mediated through the transmembrane region directly interacting with the detergent micelle or through the soluble domains of the proteins getting in close contact with detergent micelles during electrospray ionization. Here, we explore the effects of detergent micelles on soluble proteins during native mass spectrometry aiming at distinguishing these two events. Specifically, we employ two non-ionic and one zwitterionic detergents as well as a variety of standard proteins differing in size, oligomeric state and surface hydrophobicity, and evaluate the observed charge states in the absence and presence of detergents. Using ion mobility-mass spectrometry, we assess the proteins' stability as well as the ability to maintain non-covalent interactions with ligands. Finally, we examine lipid transfer from mixed detergent-lipid micelles containing the various detergents to soluble proteins. In summary, we found that C8E4 detergent reduces the proteins’ charge states, stabilizes the proteins and facilitates lipid transfer.

去污剂通常用于溶解和稳定完整的膜蛋白。先前已经描述了它们对天然质谱测量中洗涤剂溶解的膜蛋白电荷状态的影响。这些作用可以通过跨膜区直接与洗涤剂胶束相互作用或通过蛋白质的可溶性结构域在电喷雾电离过程中与洗涤剂胶束密切接触来介导。在这里，我们探索了洗涤剂胶束在天然质谱法中对可溶性蛋白质的影响，旨在区分这两个事件。具体来说，我们使用两种非离子和一种两性离子去污剂以及各种大小、寡聚状态和表面疏水性不同的标准蛋白质，并评估在不存在和存在洗涤剂的情况下观察到的电荷状态。使用离子迁移质谱法，我们评估了蛋白质的稳定性以及与配体保持非共价相互作用的能力。最后，我们检查了从含有各种洗涤剂的混合洗涤剂-脂质胶束到可溶性蛋白质的脂质转移。总之，我们发现 C8E4 去污剂降低了蛋白质的电荷状态，稳定了蛋白质并促进了脂质转移。