Volume 54, Issue 6 p. 481-487
RESEARCH ARTICLE

Influence of the amino acid composition on the ionization efficiencies of small peptides

Piia Liigand

Corresponding Author

Piia Liigand

Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Tartu, Estonia

Correspondence

Piia Liigand, Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu 50411, Estonia.

Email: [email protected]

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Karl Kaupmees

Karl Kaupmees

Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Tartu, Estonia

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Anneli Kruve

Anneli Kruve

Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Tartu, Estonia

Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany

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First published: 08 March 2019
Citations: 20

Abstract

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.