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Debiossac M, Schätti J, Kriegleder M, Geyer P, Shayeghi A, Mayor M, Arndt M, Köhler V. Tailored photocleavable peptides: fragmentation and neutralization pathways in high vacuum. Phys Chem Chem Phys 2018; 20:11412-11417. [PMID: 29645042 PMCID: PMC5932999 DOI: 10.1039/c8cp01058g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 03/23/2018] [Indexed: 01/31/2023]
Abstract
Photocleavable tags (PCTs) have the potential for excellent spatio-temporal control over the release of subunits of complex molecules. Here, we show that electrosprayed oligopeptides, functionalized by a tailored ortho-nitroarylether can undergo site-specific photo-activated cleavage under UV irradiation (266 nm) in high vacuum. The comparison of UV photodissociation (UVPD) and collision-induced dissociation (CID) points to the thermal nature of the cleavage mechanism, a picture corroborated by the temperature dependence of the process. Two competing photodissociation pathways can be identified. In one case a phenolate anion is separated from a neutral zwitterion. In the other case a neutral phenol derivative leaves a negatively charged peptide behind. To understand the factors favoring one channel over the other, we investigate the influence of the peptide length, the nature of the phenolic group and the position of the nitro-group (ortho vs. para). The observed gas phase cleavage of a para-nitro benzylic ether markedly differs from the established behavior in solution.
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Affiliation(s)
- M. Debiossac
- Faculty of Physics, University of Vienna , VCQ, Boltzmanngasse 5 , A-1090 Vienna , Austria .
| | - J. Schätti
- Department of Chemistry, University of Basel , Mattenstrasse 24a, BPR 1096 , CH-4058 Basel , Switzerland .
| | - M. Kriegleder
- Faculty of Physics, University of Vienna , VCQ, Boltzmanngasse 5 , A-1090 Vienna , Austria .
| | - P. Geyer
- Faculty of Physics, University of Vienna , VCQ, Boltzmanngasse 5 , A-1090 Vienna , Austria .
| | - A. Shayeghi
- Faculty of Physics, University of Vienna , VCQ, Boltzmanngasse 5 , A-1090 Vienna , Austria .
| | - M. Mayor
- Department of Chemistry, University of Basel , Mattenstrasse 24a, BPR 1096 , CH-4058 Basel , Switzerland .
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1 , D-76344 Eggenstein-Leopoldshafen , Germany
- Lehn Institute of Functional Materials (LIFM), Sun Yat-Sen University (SYSU) , Xingang Rd. W. , Guangzhou , China
| | - M. Arndt
- Faculty of Physics, University of Vienna , VCQ, Boltzmanngasse 5 , A-1090 Vienna , Austria .
| | - V. Köhler
- Department of Chemistry, University of Basel , Mattenstrasse 24a, BPR 1096 , CH-4058 Basel , Switzerland .
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Marksteiner M, Haslinger P, Ulbricht H, Sclafani M, Oberhofer H, Dellago C, Arndt M. Gas-phase formation of large neutral alkaline-earth metal tryptophan complexes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2008; 19:1021-1026. [PMID: 18499471 DOI: 10.1016/j.jasms.2008.04.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 04/12/2008] [Accepted: 04/14/2008] [Indexed: 05/26/2023]
Abstract
We report on the first observation of isolated large neutral metal amino acid complexes such as Trp(n)Me(k), with Me=Ca, Ba, Sr, cluster combinations covering n=1...33, k=0..2 and masses beyond 6500 u. The cluster beam is generated using UV laser desorption from a mixed powder of alkaline-earth metal salts and tryptophan inside a cluster mixing channel. The particles are detected using VUV photoionization followed by time-of-flight mass spectroscopy. The enhanced stability of metal amino acid clusters over pure amino acid clusters is substantiated in molecular dynamics simulations by determining the gain in binding energy related to the inclusion of the metal atoms.
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