Human tropoelastin sequence: dynamics of polypeptide coded by exon 6 in solution.
Calorimetric studies were performed on exon 6 in powdered form and in solution [water and 2,2,2-trifluoroethanol (TFE), a structure-inducing solvent or cosolvent]. Dynamic dielectric spectroscopy (DDS) analyses were realized in water and 20% TFE. The major role of solvent-peptide organization is evidenced with these techniques. Calorimetric measurements reveal the structural water organization around the polypeptide as well as the presence of hydrophobic interactions in TFE solution. Dielectric measurements showed for exon 6/water a decrease of relaxations times of bulk solvent implying a faster dynamics with a slight increase of the activation entropy, suggesting that exon 6 probably creates disorder within the solvent. For TFE/water mixtures, an influence of exon 6 on its environment was seen with a relaxation associated with the exon 6/solvent interactions reinforced by storage of 72 h. Finally, exon 6/solvent interactions were clearly observed with addition of TFE.
Tintar
D
D
Laboratoire de Physique des Polymères, CIRIMAT UMR 5085, Institut Carnot, Université Paul Sabatier, Toulouse, France.
Samouillan
V
V
Dandurand
J
J
Lacabanne
C
C
Pepe
A
A
Bochicchio
B
B
Tamburro
Antonio M
AM
D000595:Amino Acid Sequence; D002152:Calorimetry, Differential Scanning; D055664:Electrochemical Techniques; D005091:Exons; D006801:Humans; D008969:Molecular Sequence Data; D009391:Nephelometry and Turbidimetry; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D012997:Solvents / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature; D014270:Trifluoroethanol / Q000737:chemistry*; D014333:Tropoelastin / Q000737:chemistry* / Q000235:genetics; D014867:Water / Q000737:chemistry
D010446:Peptide Fragments; D012997:Solvents; D014333:Tropoelastin; D014867:Water; D014270:Trifluoroethanol