Vibrational Signatures of Conformer-Specific Intramolecular Interactions in Protonated Tryptophan.

Autor:	Pereverzev AY; Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Federale de Lausanne, EPFL SB ISIC LCPM , Station 6, CH-1015 Lausanne, Switzerland., Cheng X; Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States.; Henry Eyring Center for Theoretical Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States., Nagornova NS; Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Federale de Lausanne, EPFL SB ISIC LCPM , Station 6, CH-1015 Lausanne, Switzerland., Reese DL; Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States.; Henry Eyring Center for Theoretical Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States., Steele RP; Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States.; Henry Eyring Center for Theoretical Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States., Boyarkin OV; Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Federale de Lausanne, EPFL SB ISIC LCPM , Station 6, CH-1015 Lausanne, Switzerland.
Jazyk:	angličtina
Zdroj:	The journal of physical chemistry. A [J Phys Chem A] 2016 Jul 21; Vol. 120 (28), pp. 5598-608. Date of Electronic Publication: 2016 Jul 08.
DOI:	10.1021/acs.jpca.6b05605
Abstrakt:	Because of both experimental and computational challenges, protonated tryptophan has remained the last aromatic amino acid for which the intrinsic structures of low-energy conformers have not been unambiguously solved. The IR-IR-UV hole-burning spectroscopy technique has been applied to overcome the limitations of the commonly used IR-UV double resonance technique and to measure conformer-specific vibrational spectra of TrpH(+), cooled to T = 10 K. Anharmonic ab initio vibrational spectroscopy simulations unambiguously assign the dominant conformers to the two lowest-energy geometries from benchmark coupled-cluster structure computations. The match between experimental and ab initio spectra provides an unbiased validation of the calculated structures of the two experimentally observed conformers of this benchmark ion. Furthermore, the vibrational spectra provide conformer-specific signatures of the stabilizing interactions, including hydrogen bonding and an intramolecular cation-π interaction.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu