Wells J Mitchell, Chrisman Paul A, McLuckey Scott A
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA.
J Am Chem Soc. 2003 Jun 18;125(24):7238-49. doi: 10.1021/ja035051l.
Gas-phase reactions between multiply charged positive and negative protein ions are carried out in a quadrupole ion trap mass spectrometer. The ions react with one another by proton transfer and complex formation. Proton transfer products and complexes are formed via competitive processes in single ion/ion encounters. The relative contributions of proton transfer versus complex formation are dependent upon the charges of the ions as well as other characteristics of the ions yet to be clearly delineated. No fragmentation of covalent bonds of the protein reactants is observed. A model that considers the trajectories associated with ion/ion interactions appears to hold the most promise in accounting for the results. The formation of bound ion/ion orbits appears to play an important role in determining overall reaction kinetics as well as the distribution of ion/ion reaction products. Tandem mass spectrometry is used to compare protein complexes formed in the gas-phase with those formed initially in solution and subsequently liberated by electrospray; it is shown that both forms of complex dissociate similarly, but the complexes formed in the gas phase can retain a "memory" of their method of formation.
在四极杆离子阱质谱仪中进行多电荷正、负蛋白质离子之间的气相反应。离子通过质子转移和复合物形成相互反应。质子转移产物和复合物在单离子/离子碰撞中通过竞争过程形成。质子转移与复合物形成的相对贡献取决于离子的电荷以及尚未明确界定的离子的其他特性。未观察到蛋白质反应物共价键的断裂。一个考虑与离子/离子相互作用相关轨迹的模型似乎在解释结果方面最有前景。结合离子/离子轨道的形成似乎在决定整体反应动力学以及离子/离子反应产物的分布方面起着重要作用。串联质谱用于比较气相中形成的蛋白质复合物与最初在溶液中形成并随后通过电喷雾释放的复合物；结果表明，两种形式的复合物解离方式相似，但气相中形成的复合物可以保留其形成方法的“记忆”。
