Conformation-specific spectroscopy and photodissociation of cold, protonated tyrosine and phenylalanine.

Details

Serval ID
serval:BIB_7183D52C78C2
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Conformation-specific spectroscopy and photodissociation of cold, protonated tyrosine and phenylalanine.
Journal
Journal of the American Chemical Society
Author(s)
Stearns J.A., Mercier S., Seaiby C., Guidi M., Boyarkin O.V., Rizzo T.R.
ISSN
0002-7863 (Print)
ISSN-L
0002-7863
Publication state
Published
Issued date
26/09/2007
Peer-reviewed
Oui
Volume
129
Number
38
Pages
11814-11820
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
We present here ultraviolet and infrared spectra of protonated aromatic amino acids in a cold, 22-pole ion trap. Ultraviolet photofragmentation spectra of protonated tyrosine and phenylalanine show vibronically resolved bands corresponding to different stable conformers: two for PheH+ and four in the case of TyrH+. We subsequently use the resolved UV spectra to perform conformer-specific infrared depletion spectroscopy. Comparison of the measured infrared spectra to density functional theory calculations helps assign the geometry of the various conformers, all of which exhibit NH...pi hydrogen bonds and NH...O=C interactions, with the COOH group oriented either anti or gauche to the aromatic ring. In both molecules the majority of the observed fragments result from dissociation on an excited electronic state. In TyrH+, different conformers excited with practically the same energy exhibit different fragmentation patterns, suggesting that the excited-state dynamics depend upon conformation.
Keywords
Algorithms, Cold Temperature, Mass Spectrometry/methods, Molecular Conformation, Phenylalanine/chemistry, Phenylalanine/metabolism, Photochemistry, Protons, Spectrophotometry, Infrared/methods, Tyrosine/chemistry, Tyrosine/metabolism, Ultraviolet Rays
Pubmed
Web of science
Create date
19/06/2019 15:45
Last modification date
20/08/2019 15:29
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