English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Probing chirality recognition of protonated glutamic acid dimers by gas-phase vibrational spectroscopy and first-principles simulations

MPS-Authors
/persons/resource/persons86773

Schneider,  Markus
Theory, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons21325

Baldauf,  Carsten
Theory, Fritz Haber Institute, Max Planck Society;
Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)

c8cp05855e.pdf
(Publisher version), 4MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Klyne, J., Bouchet, A., Ishiuchi, S.-i., Fujii, M., Schneider, M., Baldauf, C., et al. (2018). Probing chirality recognition of protonated glutamic acid dimers by gas-phase vibrational spectroscopy and first-principles simulations. Physical Chemistry Chemical Physics, 20(45), 28452-28464. doi:10.1039/c8cp05855e.


Cite as: http://hdl.handle.net/21.11116/0000-0002-CDDE-E
Abstract
The homochirality of the amino acid metabolism still puzzles biochemists. Vibrational spectroscopy of mass- selected gas-phase amino acids and their clusters can precisely reveal their conformation and might ultimately help to decode the interactions responsible for chirality recognition. Infrared photo- dissociation (IRPD) and conformer-selective IR–IR hole burning spectra of protonated glutamic acid dimers (LL-/LD-Glu2H+) recorded in the fingerprint and XH stretch ranges (1100–1900 and 2600–3600 cm-1) provide direct insight into their stereospecific interactions. Glu2H+ dimers are generated by electrospray ionization and stored in a cryogenic quadrupole ion trap held at 10 K. The assignment of the IRPD spectra is supported by vibrational analysis using many-body dispersion-corrected hybrid density-functional theory. Sampling of the conformational space is accomplished by basin hopping and replica-exchange molecular dynamics simulations. The most stable LD-Glu2H+ dimer (LD1) is predicted to be more stable than the most stable LL-Glu2H+ dimer (LL1) by DE0 = 4.0kJmol-1, which relies on stronger secondary interactions in LD1 as demonstrated by the noncovalent interaction method. IR–IR hole burning spectroscopy reveals the coexistence of at least four LD-Glu2H+ and three LL-Glu2H+ conformers. Their IR-dip spectra are assigned to the most stable conformers at room and cryogenic temperature, revealing incomplete thermalization of the ions by kinetic trapping in the cold trap. We observe different population ratios of LL and LD conformers of Glu2H+, as revealed by specific nNH2 and nCO intensities (fingerprints of chirality recognition).