Experimental study of the assignment of non-amide Raman bands of the polypentapeptide of elastin,poly(VPGVG)

Poly(VPGVG) is the main member of a novel group of biopolymers showing exceptional potential for future applications in different fields such as biomedical, environmental, energy and industrial areas. Taking into account their future development, further knowledge is needed to understand the molecular basis of their remarkable behaviour and other structural and technical parameters. This paper is devoted to the study of its Raman spectrum. There is only one report in the literature dealing with a vibrational band assignment for this compound, and this assignment was made on a speculative basis. The present work was intended to add further experimental support to this unique tentative assignment. To achieve this goal, the Raman spectra of 17 peptides and polypeptides, containing exclusively the amino acids valine, proline and/or glycine, were studied and compared. Two Raman bands of the polymer spectrum, at 1123 and 1342 cm⁻¹, seemed to be associated with localized vibrations of the valine side-chain. Copyright © 2000 John Wiley & Sons, Ltd.