1JLO

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

Summary for 1JLO

• Entry DOI: 10.2210/pdb1jlo/pdb
• Related: 1AS5
• NMR Information: BMRB: 5113
• Descriptor: PSI-CONOTOXIN PIIIE (1 entity in total)
• Functional Keywords: multiple disulfide bonds, amidated c-terminus, toxin
• Cellular location: Secreted: P56529
• Total number of polymer chains: 1
• Total formula weight: 2727.18

Authors

Van Wagoner, R.M.,Ireland, C.M. (deposition date: 2001-07-16, release date: 2003-06-24, Last modification date: 2025-03-26)

Primary citation

Van Wagoner, R.M.,Ireland, C.M.
An Improved Solution Structure for psi-Conotoxin Piiie
Biochemistry, 42:6347-6352, 2003

PubMed Abstract: 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.

PubMed: 12767215
DOI: 10.1021/bi027274e

Experimental method

SOLUTION NMR