Liigand Piia, Kaupmees Karl, Kruve Anneli
Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Tartu, Estonia.
Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany.
J Mass Spectrom. 2019 Jun;54(6):481-487. doi: 10.1002/jms.4348.
Electrospray ionization is widely used to generate gas phase ions from a variety of molecules ranging from small ions to large proteins, while the ionization mechanism is claimed to depend on the size of the molecule. For small molecules, the ionization efficiency, the amount of gas phase ions produced in the electrospray process, depends on the properties of the compound. Here, we show that the amino acid composition also influences the ionization efficiency of the oligopeptide. Additionally, we show that the ionization efficiencies of oligopeptides consisting of more than five amino acid residues are very similar to one another, and assuming equal ionization efficiencies is feasible. Therefore, accurate ionization efficiency predictions are needed mainly for small oligopeptides. For these oligopeptides, the amino acid composition can be used to estimate the ionization efficiency in an easy to use manner.
电喷雾电离被广泛用于从小离子到大型蛋白质等各种分子生成气相离子，而电离机制据称取决于分子大小。对于小分子而言，电离效率，即在电喷雾过程中产生的气相离子量，取决于化合物的性质。在此，我们表明氨基酸组成也会影响寡肽的电离效率。此外，我们表明由五个以上氨基酸残基组成的寡肽的电离效率彼此非常相似，并且假设电离效率相等是可行的。因此，主要对于小寡肽才需要准确的电离效率预测。对于这些寡肽，氨基酸组成可用于以一种易于使用的方式估计电离效率。
