title: Nuclear magnetic resonance studies of the snake toxin echistatin. 1H resonance assignments and secondary structure.
abstract: The 1H-NMR spectrum of the snake toxin echistatin has been assigned using homonuclear two-dimensional methods. Consideration of the NOE patterns, coupling constants and putative hydrogen bonds enabled two regular features of secondary structure to be deduced: a beta-sheet/turn between residues 8 and 13 and a small anti-parallel beta-sheet and bulge linking residues 16-20 with residues 30-33. The recognition region of the protein containing the residues RGD lies in a loop joining the two strands of the beta-sheet. The beta-bulge and the loop containing the RGD sequence undergo pH-dependent conformational interconversion, modulated by the side chain of Asp29.
authors.affiliation: Glaxo Group Research, Greenford, England.
authors.forename: R M
authors.initials: RM
authors.lastname: Cooke
authors.forename: B G
authors.initials: BG
authors.lastname: Carter
authors.forename: D M
authors.initials: DM
authors.lastname: Martin
authors.forename: P
authors.initials: P
authors.lastname: Murray-Rust
authors.forename: M P
authors.initials: MP
authors.lastname: Weir
mesh_terms: D000595:Amino Acid Sequence; D036341:Intercellular Signaling Peptides and Proteins; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides; D011487:Protein Conformation; D014757:Viper Venoms / Q000737:chemistry*
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D014757:Viper Venoms; C057986:echistatin