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Indication of 3₁₀-Helix Structure in Gas-Phase Neutral Pentaalanine.

ABSTRACT: We investigate the gas-phase structure of the neutral pentaalanine peptide. The IR spectrum in the 340-1820 cm^-1 frequency range is obtained by employing supersonic jet cooling, infrared multiphoton dissociation, and vacuum-ultraviolet action spectroscopy. Comparison with quantum chemical spectral calculations suggests that the molecule assumes multiple stable conformations, mainly of two structure types. In the most stable conformation theoretically found, the N-terminus forms a C5 ring and the backbone resembles that of an 3₁₀-helix with two β-turns. Additionally, the conformational preferences of pentaalanine have been evaluated using Born-Oppenheimer molecular dynamics, showing that a nonzero simulation time step causes a systematic frequency shift.

SUBMITTER: Andersson A

PROVIDER: S-EPMC9900583 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature

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Indication of 310-Helix Structure in Gas-Phase Neutral Pentaalanine.

Andersson Åke Å Yatsyna Vasyl V Linares Mathieu M Rijs Anouk A Zhaunerchyk Vitali V

The journal of physical chemistry. A 20230120 4

We investigate the gas-phase structure of the neutral pentaalanine peptide. The IR spectrum in the 340-1820 cm-1 frequency range is obtained by employing supersonic jet cooling, infrared multiphoton dissociation, and vacuum-ultraviolet action spectroscopy. Comparison with quantum chemical spectral calculations suggests that the molecule assumes multiple stable conformations, mainly of two structure types. In the most stable conformation theoretically found, the N-terminus forms a C5 r ...[more]

PMID: 36669091

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