Solution conformation of a model hexapeptide containing RGD sequence.
The solution conformation of a model hexapeptide Asp-Arg-Gly-Asp-Ser-Gly (DRGDSG) containing the RGD sequence has been studied in DMSO-d6 as well as in aqueous solution (H2O:D2O/90:10%) by 1H NMR spectroscopy. The unambiguous identification of spin systems of various amino acid residues and sequence specific assignment of all proton resonances was achieved by a combination of two dimensional COSY and NOESY experiments. The temperature coefficient data of the amide proton chemical shifts in conjunction with the vicinal coupling constants, i.e. 3JNH-C alpha H, NOESY and ROESY results indicate that the peptide in both the solvents exists in a blend of conformers with beta-sheet like extended backbone structure and folded conformations. The folded conformers do not appear to be stabilised by intramolecular hydrogen bonding. Our results are consistent with the flexibility of RGD segment observed in the NMR studies on the protein echistatin containing the RGD motif (references 23-25).
Dhingra
M M
MM
Chemical Physics Group, Tata Institute of Fundamental Research, Bombay, India.
D000595:Amino Acid Sequence; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D011487:Protein Conformation; D012996:Solutions
D009842:Oligopeptides; D012996:Solutions; C047981:arginyl-glycyl-aspartic acid