Summary for 1NXN
| Entry DOI | 10.2210/pdb1nxn/pdb |
| NMR Information | BMRB: 5608 |
| Descriptor | CONTRYPHAN-VN, MAJOR FORM (CIS CONFORMER) (1 entity in total) |
| Functional Keywords | d-tryptophan, cyclic peptide, disulfide bridge, cis-trans isomerism, toxin |
| Biological source | synthetic construct |
| Total number of polymer chains | 1 |
| Total formula weight | 1090.28 |
| Authors | Eliseo, T.,Cicero, D.O.,Polticelli, F.,Schinina, M.E.,Massilia, G.R.,Paci, M.,Ascenzi, P. (deposition date: 2003-02-11, release date: 2003-03-04, Last modification date: 2024-10-30) |
| Primary citation | Eliseo, T.,Cicero, D.O.,Romeo, C.,Schinina, M.E.,Massilia, G.R.,Polticelli, F.,Ascenzi, P.,Paci, M. Solution structure of the cyclic peptide contryphan-Vn, a Ca2+-dependent K+ channel modulator Biopolymers, 74:189-198, 2004 Cited by PubMed Abstract: The solution structure of contryphan-Vn, a cyclic peptide with a double cysteine S-S bridge and containing a D-tryptophan extracted from the venom of the cone snail Conus ventricosus, has been determined by NMR spectroscopy using a variety of homonuclear and heteronuclear NMR methods and restrained molecular dynamics simulations. The main conformational features of backbone contryphan-Vn are a type IV beta-turn from Gly 1 to Lys 6 and a type I beta-turn from Lys 6 to Cys 9. As already found in other contryphans, one of the two prolines--the Pro4--is mainly in the cis conformation while Pro7 is trans. A small hydrophobic region probably partly shielded from solvent constituted from the close proximity of side chains of Pro7 and Trp8 was observed together with a persistent salt bridge between Asp2 and Lys6, which has been revealed by the diagnostic observation of specific nuclear Overhauser effects. The salt bridge was used as a restraint in the molecular dynamics in vacuum but without inserting explicit electrostatic contribution in the calculations. The backbone of the unique conformational family found of contryphan-Vn superimposes well with those of contryphan-Sm and contryphan-R. This result indicates that the contryphan structural motif represents a robust and conserved molecular scaffold whose main structural determinants are the size of the intercysteine loop and the presence and location in the sequence of the D-Trp and the two Pro residues. PubMed: 15150794DOI: 10.1002/bip.20025 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
Download full validation report
