1jlo

Solution Structure of the Noncompetitive Skeletal Muscle Nicotinic Acetylcholine Receptor Antagonist Psi-conotoxin PIIIE

spinqualitylabelsall models 1jlo Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1jlo is a 1 chain structure with sequence from Conus purpurascens. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR, 13 models Ligands: HYP, NH2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CM3E_CONPU Psi-conotoxins act on postsynaptic membranes, and act as non-competitive antagonist of nicotinic acetylcholine receptors (nAChR). Is more toxic than Psi-conotoxin PIIIF. Has paralytic activity when injected intraperitoneally into goldfish. Publication Abstract from PubMed A revised, high-resolution structure of psi-conotoxin Piiie (psi-Piiie), a noncompetitive inhibitor of the nicotinic acetylcholine receptor (nAChR), produced through the use of NMR and molecular modeling calculations is presented. The original structures of psi-Piiie had a relatively high degree of disorder, particularly in the conformation of the disulfide bridges. Our studies utilized (13)C-labeling of selected cysteine residues allowing the resolution of all problems of resonance overlap for the cysteine residues. The improved data were used to produce a new set of structures by a molecular modeling process incorporating relaxation matrix methods for the determination of interproton distance restraints and a combination of distance geometry and simulated annealing for structure generation. The structures produced are very well converged with the RMSD of backbone atom positions of the main body of the peptide improving from 0.73 to 0.13 A. Other indicators of correlation with the experimental data and quality of covalent geometry showed significant improvement in the new structures. The overall conformation of the peptide backbone is similar between the two determinations with the exception of the N-terminus. This difference leads to a significant effect on the predicted distribution of positive charge within psi-Piiie, a property likely to influence interpretation of future mutational studies. An improved solution structure for psi-conotoxin PiiiE.,Van Wagoner RM, Ireland CM Biochemistry. 2003 Jun 3;42(21):6347-52. PMID:12767215 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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