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Ultraviolet laser-induced cross-linking in peptides

Authors

  • Gabriella Leo,

    1. Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, Napoli, Italy
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    • These authors contributed equally to this work.

  • Carlo Altucci,

    1. Dipartimento di Scienze Fisiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, Napoli, Italy
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    • These authors contributed equally to this work.

  • Sandrine Bourgoin-Voillard,

    1. Center for Biomedical Mass Spectrometry, Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
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  • Alfredo M. Gravagnuolo,

    1. Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, Napoli, Italy
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  • Rosario Esposito,

    1. Dipartimento di Scienze Fisiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, Napoli, Italy
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  • Gennaro Marino,

    1. Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, Napoli, Italy
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  • Catherine E. Costello,

    1. Center for Biomedical Mass Spectrometry, Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
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  • Raffaele Velotta,

    1. Dipartimento di Scienze Fisiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, Napoli, Italy
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  • Leila Birolo

    Corresponding author
    • Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, Napoli, Italy
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Correspondence to: L. Birolo, Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Universitario di Monte S.Angelo, 80126 Napoli, Italy.

E-mail: birolo@unina.it

Abstract

RATIONALE

The aim of this study was to demonstrate, and to characterize by high-resolution mass spectrometry that it is possible to preferentially induce covalent cross-links in peptides by using high-energy femtosecond ultraviolet (UV) laser pulses. The cross-link is readily formed only when aromatic amino acids are present in the peptide sequence.

METHODS

Three peptides, xenopsin, angiotensin I, and interleukin, individually or in combination, were exposed to high-energy femtosecond UV laser pulses, either alone or in the presence of spin trapping molecules, the reaction products being characterized by high resolution mass spectrometry.

RESULTS

High-resolution mass spectrometry and spin trapping strategies showed that cross-linking occurs readily, proceeds via a radical mechanism, and is the highly dominant reaction, proceeding without causing significant photo-damage in the investigated range of experimental parameters.

CONCLUSIONS

High-energy femtosecond UV laser pulses can be used to induce covalent cross-links between aromatic amino acids in peptides, overcoming photo-oxidation processes, that predominate as the mean laser pulse intensity approaches illumination conditions achievable with conventional UV light sources. Copyright © 2013 John Wiley & Sons, Ltd.

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