A 1H NMR study on the interaction of aminoxyl paramagnetic probes with unfolded peptides

Abstract

The use of soluble spin labels to filter out the cross peaks of outer proton nuclei in 2D NMR spectra has been proposed as a general method to obtain structural information for complex molecules. Here the paramagnetic effects observed on backbone protons of an unfolded 27 amino acid peptide are discussed. The lack of any differential intensity change of the NH–Hα cross-peaks in TOCSY spectra is suggested as an additional general criterion for the identification of unfolded structures.