1H-NMR conformational analysis of a high-affinity antigenic 11-residue peptide from the tryptophan synthase beta 2 subunit.

Muriel Delepierre (1) , Marie-Pierre Larvor (1) , Françoise Baleux (2) , Michel E. Goldberg (1)

1 Biochimie cellulaire
2 Chimie Organique

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.

Muriel Delepierre, Marie-Pierre Larvor, Françoise Baleux, Michel E. Goldberg. 1H-NMR conformational analysis of a high-affinity antigenic 11-residue peptide from the tryptophan synthase beta 2 subunit.. European Journal of Biochemistry, 1991, 201 (3), pp.681-93. ⟨10.1111/j.1432-1033.1991.tb16329.x⟩. ⟨pasteur-00390547⟩