Electric dipole moments and conformations of isolated peptides
نویسندگان
چکیده
The electric dipole moments of the isolated amino acid tryptophan and small glycine-based peptides (WGn, n = 1−5, 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
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