Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, Liège 4000, Belgium.
University of Bordeaux, INSERM and CNRS, Laboratoire Acides Nucléiques: Régulations Naturelles et Artificielles (ARNA, U1212, UMR5320), IECB, Pessac 33600, France.
Anal Chem. 2020 Mar 17;92(6):4573-4582. doi: 10.1021/acs.analchem.9b05850. Epub 2020 Mar 4.
Modern ion mobility instrumentation is typically operated above the low field limit, which may activate the ions and cause structural rearrangement or fragmentation during analysis. Here, we quantitatively assessed the internal heating experienced by ions during trapped ion mobility spectrometry (TIMS) experiments. To this end, the fragmentation yields of fragile benzylpyridinium "thermometer" ions were monitored during both the accumulation and analysis steps inside the TIMS tunnel. The corresponding fragmentation rate constants were translated into a vibrational effective temperature . Our results demonstrate significant fragmentation upstream and inside the TIMS tunnel that corresponds to ≈ 510 K during both the accumulation and analysis steps. Broadening our scope to cytochrome and lysozyme, we showed that although compact "native" folds can be preserved, the collision cross section distributions are highly sensitive to the transmission voltages and the analysis time scale. Our results are discussed with regard to data previously acquired on traveling-wave (TWIMS) ion mobility in the context of native mass spectrometry and conformational landscape exploration.
现代离子淌度仪器通常在低场限以上运行，这可能会在分析过程中激活离子并导致结构重排或碎片化。在这里，我们定量评估了在囚禁离子淌度谱（TIMS）实验中离子内部所经历的加热。为此，我们在 TIMS 隧道内的积累和分析步骤中监测了脆弱的苄基吡啶鎓“温度计”离子的碎裂产率。相应的碎裂速率常数被转化为振动有效温度 。我们的结果表明，在积累和分析步骤中，TIMS 隧道的上游和内部都存在显著的碎片化，对应的温度约为 510 K。将我们的研究范围扩大到细胞色素 c 和溶菌酶，我们表明，尽管可以保留紧凑的“天然”折叠，但碰撞截面分布对传输电压和分析时间尺度高度敏感。我们的结果结合了之前在原生质谱和构象景观探索背景下在 traveling-wave (TWIMS)离子淌度上获得的数据进行了讨论。
