title: An alternative structure model for the polypentapeptide in elastin.
abstract: Polypentapeptides (GVGVP)n which are designed in analogy to the connective tissue protein elastin are reported to transform various kinds of energy into mechanical work by the so-called deltaT(t)-mechanism in cross-linked macroscopic polypentapeptide (PPP) films. In the literature, the responsible element of conformation in such polypeptides is described as a beta-spiral and the deltaT(t) effect is explained as a sudden change of macroconformation of single polypeptide molecules from an extended but not regular state below a transition temperature T(t) to the beta-spiral above T(t). We examined the secondary structure of the linear PPP C(GVGVP)6 in solution with DSC, CD, UV absorption, FTIR and NMR spectroscopy. The results suggest that the beta-spiral is not present in the conformational structure of the PPP molecules. The antiparallel beta-sheet is proposed to be the basic regular part of conformation because it agrees with all spectroscopic data. As a consequence, the elasticity of natural elastin must be considered from a new perspective.
authors.affiliation: Fraunhofer-Institute for Manufacturing and Applied Materials Research (IFAM), Wiener Strasse 12, D-28359 Bremen, Germany.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Gross
authors.forename: Wulff
authors.initials: W
authors.lastname: Possart
authors.forename: Michael
authors.initials: M
authors.lastname: Zeppezauer
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004549:Elastin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010455:Peptides; D012996:Solutions; C033943:elastin polypentapeptide; D004549:Elastin