Cooke R M, Carter B G, Martin D M, Murray-Rust P, Weir M P
Glaxo Group Research, Greenford, England.
Eur J Biochem. 1991 Dec 5;202(2):323-8. doi: 10.1111/j.1432-1033.1991.tb16379.x.
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.
