1H-NMR conformational analysis of a high-affinity antigenic 11-residue peptide from the tryptophan synthase beta 2 subunit.
Two synthetic peptides from the beta 2 subunit of tryptophan synthase have been studied by 1H-NMR spectroscopy at 300 MHz. One peptide, His-Gly-Arg-Val-Gly-Ile-Tyr-Phe-Gly-Met-Lys (peptide 11; Ile, isoleucine) is antigenic and binds with a high affinity to a monoclonal antibody that recognizes the native beta 2 subunit. The second peptide, His-Gly-Arg-Val-Gly-Ile-Tyr-Phe (peptide 8) reacts very weakly with the antibody. The 1H-NMR spectra of the two peptides have been assigned from two-dimensional techniques in H2O, 2H2O and (2H6) dimethyl sulfoxide [(2H6)Me2SO]. The structure has been evaluated through analysis of nuclear Overhauser effects, coupling constants, amide-proton exchange rates and their temperature coefficients, and chemical shifts. In aqueous solvent, the C-terminal part of peptide 11 presents some structure centered around residues Phe-Gly-Met. The relationship between the structure found in peptide 11 and its antigenic nature is discussed.
Delepierre
M
M
Unité de Biochimie Cellulaire, Centre National de la Recherche Scientifique, Institut Pasteur, Paris, France.
Larvor
M P
MP
Baleux
F
F
Goldberg
M E
ME
D000595:Amino Acid Sequence; D000939:Epitopes / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D011487:Protein Conformation; D011522:Protons; D012997:Solvents; D013816:Thermodynamics; D014367:Tryptophan Synthase / Q000737:chemistry* / Q000276:immunology*
D000939:Epitopes; D010446:Peptide Fragments; D011522:Protons; D012997:Solvents; D014367:Tryptophan Synthase