Department of Chemistry, Texas A&M University , College Station, Texas 77843, United States.
Anal Chem. 2016 Jun 7;88(11):5934-40. doi: 10.1021/acs.analchem.6b00871. Epub 2016 May 10.
Electrospray ionization (ESI) of ubiquitin from acidified (0.1%) aqueous solution produces abundant ubiquitin-chloride adduct ions, [M + nH + xCl]((n - x)+), that upon mild heating react via elimination of neutral HCl. Ion mobility collision cross section (CCS) measurements show that ubiquitin ions retaining chloride adducts exhibit CCS values similar to those of the "native-state" of the protein. Coupled with results from recent molecular dynamics (MD) simulations for the evolution of a salt-containing electrospray droplet, this study provides a more complete picture for how the presence of salts affects the evolution of protein conformers in the final stages of dehydration of the ESI process and within the instrument.
电喷雾电离（ESI）从酸化（0.1%）水溶液中的泛素产生丰富的泛素-氯加合物离子，[M + nH + xCl]（（n - x）+），这些离子在温和加热下通过消除中性 HCl 反应。离子迁移率碰撞截面（CCS）测量表明，保留氯加合物的泛素离子表现出与蛋白质“天然状态”相似的 CCS 值。结合最近含有盐的电喷雾液滴演变的分子动力学（MD）模拟结果，这项研究提供了更完整的图像，说明盐的存在如何影响 ESI 过程最后阶段脱水和仪器内蛋白质构象的演变。
