Two-dimensional 1H-NMR study of synthetic peptides containing the main immunogenic region of the Torpedo acetylcholine receptor.
A comparative 1H-NMR spectral study of a synthetic decapeptide containing the main immunogenic region of the Torpedo acetylcholine receptor (AChR; WNPADYGGIK, representing the alpha 67-76 fragment of Torpedo AChR) with four analogous peptides (WNP3-D5YGGIK, WNPAA5YGGIK, WNPADYGGA9K, and WNPD4DYGGV9K) has been carried out in dimethyl sulfoxide. One- and two-dimensional nmr experiments [correlated spectroscopy (COSY), relayed COSY, and phase-sensitive nuclear Overhauser enhancement spectroscopy (NOESY)] were performed to obtain complete assignments of the proton resonances. The presence of strong and multiple short- and long-range NOEs, and especially a strong long-range NOE between the two Asn2-C alpha H and Gly7-C alpha H protons, argues in favor of a rigid folded structure in all five cases. Temperature dependence measurements indicate the existence of three intramolecular interactions involving the Asp3, Gly8, and Lys10 amide protons.
Cung
M T
MT
Marraud
M
M
Hadjidakis
I
I
Bairaktari
E
E
Sakarellos
C
C
Kokla
A
A
Tzartos
S
S
D000595:Amino Acid Sequence; D000939:Epitopes; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis; D011487:Protein Conformation; D011950:Receptors, Cholinergic / Q000276:immunology
D000939:Epitopes; D009842:Oligopeptides; D011950:Receptors, Cholinergic; D006859:Hydrogen