Triple resonance-based 13 C α and 13 C β CEST experiments for studies of ms timescale dynamics in proteins
Abstract
A pair of triple resonance based CEST pulse schemes are presented for measuring 13Cα and 13Cβ chemical shifts of sparsely populated and transiently formed conformers that are invisible to traditional NMR experiments. CEST profiles containing dips at resonance positions of 13Cα or 13Cβ spins of major (ground) and minor (excited) conformers are obtained in a pseudo 3rd dimension that is generated by quantifying modulations of cross peaks in 15N, 1HN correlation spectra. An application to the folding reaction of a G48A mutant of the Fyn SH3 domain is presented, illustrating and validating the methodology.
Source: Journal of Biomolecular NMR