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Updated: Jul 5, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
IR/UV spectra and quantum chemical calculations of Trp-Ser: stacking interactions between backbone and indole
Thomas Häber1, Kai Seefeld, Gernot Engler
1Institut für Physikalische Chemie, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany.
Abstract:
We present infrared-UV double resonance spectra and quantum chemical calculations of the natural di-peptide H-Trp-Ser-OH. Two conformers are present in the supersonic expansions. They have a compact folded structure with two hydrogen bonds and with the serin residue stacked above the indole ring and an unusual NH(Trp)...O=C interaction in the lowest energy conformer. Conformational assignments are based on comparison with calculated (B97-D/TZV2P) structures and vibrational frequencies. Inclusion of dispersion in the quantum chemical calculations is mandatory for an accurate description of the conformer energies. We provide comparisons between methods often used in biochemistry and the dispersion-corrected double hybrid functional (B2PLYP-D) as a reference. Only concerted experimental and theoretical studies can unravel the conformational complexity already present in a dipeptide.
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