Schätti J, Sezer U, Pedalino S, Cotter J P, Arndt M, Mayor M, Köhler V
University of Basel, Department of Chemistry, Basel, 4056, Switzerland.
University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090, Vienna, Austria.
J Mass Spectrom. 2017 Aug;52(8):550-556. doi: 10.1002/jms.3959.
Amino acids are essential building blocks of life, and fluorinated derivatives have gained interest in chemistry and medicine. Modern mass spectrometry has enabled the study of oligo- and polypeptides as isolated entities in the gas phase, but predominantly as singly or even multiply charged species. While laser desorption of neutral peptides into adiabatically expanding supersonic noble gas jets is possible, UV-VIS spectroscopy, electric or magnetic deflectometry as well as quantum interferometry would profit from the possibility to prepare thermally slow molecular beams. This has typically been precluded by the fragility of the peptide bond and the fact that a peptide would rather 'fry', i.e. denature and fragment than 'fly'. Here, we explore how tailored perfluoroalkyl functionalization can reduce the intermolecular binding and thus increase the volatility of peptides and compare it to previously explored methylation, acylation and amidation of peptides. We show that this strategy is essential and enables the formation of thermal beams of intact neutral tripeptides, whereas only fragments were observed for an extensively fluoroalkyl-decorated nonapeptide. © 2017 The Authors. Journal of Mass Spectrometry Published by John Wiley & Sons Ltd.
氨基酸是生命必不可少的组成部分，而氟化衍生物在化学和医学领域引起了人们的兴趣。现代质谱技术已能够将寡肽和多肽作为气相中的孤立实体进行研究，但主要是作为单电荷甚至多电荷物种。虽然将中性肽激光解吸到绝热膨胀的超音速惰性气体射流中是可行的，但紫外 - 可见光谱、电或磁偏转测量以及量子干涉测量将受益于制备热慢分子束的可能性。这通常因肽键的脆弱性以及肽更倾向于“煎炸”（即变性和碎片化）而非“飞行”这一事实而受到阻碍。在此，我们探讨了定制的全氟烷基官能化如何降低分子间结合力，从而提高肽的挥发性，并将其与先前探索的肽的甲基化、酰化和酰胺化进行比较。我们表明，该策略至关重要，能够形成完整中性三肽的热束，而对于一个广泛用氟烷基修饰的九肽，仅观察到了片段。© 2017作者。《质谱学报》由约翰·威利父子有限公司出版
