https://doi.org/10.1140/epjd/e2002-00149-4
Electric dipole moments and conformations of isolated peptides
1
Laboratoire de Spectrométrie Ionique et Moléculaire (UMR 5579 du CNRS) ,
Université Lyon I et CNRS,
43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex, France
2
Department of Chemistry, Northwestern University
2145 Sheridan Road, Evanston, Illinois, 60208, USA
Corresponding author: a antoine@lasim.univ-lyon1.fr
Received:
4
January
2002
Published online:
13
September
2002
The electric dipole moments of the isolated amino acid tryptophan and small glycine-based peptides (WGn, 
, W = tryptophan, G = glycine) have been measured by deflection
of a molecular beam in an inhomogeneous electric field. The measurements are compared to
the results of ab initio calculations and Monte-Carlo simulations. The conformation and the
flexibility of the peptides, at different temperatures, are discussed. The WGn peptides are much
more floppy than an isolated tryptophan, even a single glycine is enough to make the peptide
floppy on the timescale of the electric deflection measurements.
PACS: 87.15.-v – Biomolecules: structure and physical properties / 33.15.Kr – Electric and magnetic moments (and derivatives), polarizability, and magnetic susceptibility
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002
