Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, OX1 3QZ (UK).
Angew Chem Int Ed Engl. 2015 Apr 7;54(15):4577-81. doi: 10.1002/anie.201411622. Epub 2015 Feb 18.
Despite the growing importance of the mass spectrometry of membrane proteins, it is not known how their transfer from solution into vacuum affects their stability and structure. To address this we have carried out a systematic investigation of ten membrane proteins solubilized in different detergents and used mass spectrometry to gain physicochemical insight into the mechanism of their ionization and desolvation. We show that the chemical properties of the detergents mediate the charge state, both during ionization and detergent removal. Using ion mobility mass spectrometry, we monitor the conformations of membrane proteins and show how the surface charge density dictates the stability of folded states. We conclude that the gas-phase stability of membrane proteins is increased when a greater proportion of their surface is lipophilic and is consequently protected by the physical presence of the micelle.
尽管膜蛋白的质谱分析越来越重要，但人们尚不清楚它们从溶液转移到真空中如何影响其稳定性和结构。为了解决这个问题，我们系统地研究了十种用不同去污剂溶解的膜蛋白，并利用质谱法深入了解它们离子化和去溶剂化的机制。我们表明，去污剂的化学性质在离子化和去污剂去除过程中都调节着荷质比。通过离子淌度质谱法，我们监测了膜蛋白的构象，并展示了表面电荷密度如何决定折叠状态的稳定性。我们得出结论，当膜蛋白表面更大比例具有亲脂性时，其气相稳定性会增加，因此会受到胶束物理存在的保护。
