Jump to main content
Jump to site search

Issue 41, 2010
Previous Article Next Article

Is β-homo-proline a pseudo-γ-turn forming element of β-peptides? An IR and VCD spectroscopic study on Ac-β-HPro-NHMe in cryogenic matrices and solutions

Author affiliations

Abstract

In order to test the pseudo-γ-turn forming capability of β-homo-proline3-HPro) 2-[(2S)-1-acetylpyrrolidin-2-yl]-N-methylacetamide (Ac-β3-HPro-NHMe) was synthesized and its potential energy landscape was investigated by infrared (IR) and vibrational circular dichroism (VCD) spectroscopy combined with density functional calculations. Based upon a comparison between experimental and computed spectra three different pseudo-γ-turn-like trans conformers and a cis conformer were identified in low-temperature Ar and Kr matrices. The computations in agreement with the observations reveal that, in contrast to its α-Pro analogue, the room-temperature abundance of the cis conformer is significant, falling above 10% in the isolated phase. Furthermore, solution-phase vibrational spectra and computations show that the cis conformer is predominant in polar solvents. This result indicates that β3-HPro is significantly less apt to form pseudo-γ-turns when compared to the γ-turn forming tendency of α-proline. The present study also shows that the interpretation of solution-phase VCD spectra of flexible molecules should be done with extra caution.

Graphical abstract: Is β-homo-proline a pseudo-γ-turn forming element of β-peptides? An IR and VCD spectroscopic study on Ac-β-HPro-NHMe in cryogenic matrices and solutions

Back to tab navigation

Supplementary files

Publication details

The article was received on 06 Apr 2010, accepted on 15 Jul 2010 and first published on 20 Sep 2010


Article type: Paper
DOI: 10.1039/C0CP00145G
Phys. Chem. Chem. Phys., 2010,12, 13603-13615

  •   Request permissions

    Is β-homo-proline a pseudo-γ-turn forming element of β-peptides? An IR and VCD spectroscopic study on Ac-β-HPro-NHMe in cryogenic matrices and solutions

    S. Góbi, K. Knapp, E. Vass, Z. Majer, G. Magyarfalvi, M. Hollósi and G. Tarczay, Phys. Chem. Chem. Phys., 2010, 12, 13603
    DOI: 10.1039/C0CP00145G

Search articles by author

Spotlight

Advertisements