EPIC- and CHANCE-HSQC: two 15N-photo-CIDNP-enhanced pulse sequences for the sensitive detection of solvent-exposed tryptophan.

ABSTRACT: Photochemically induced dynamic nuclear polarization (photo-CIDNP) of nuclei other than (1)H offers a tremendous potential for sensitivity enhancement in liquid state NMR under mild, physiologically relevant conditions. Photo-CIDNP enhancements of (15)N magnetization are much larger than those typically observed for (1)H. However, the low gyromagnetic ratio of (15)N prevents a full fruition of the potential signal-to-noise gains attainable via (15)N photo-CIDNP. Here, we propose two novel pulse sequences, EPIC- and CHANCE-HSQC, tailored to overcome the above limitation. EPIC-HSQC exploits the strong (1)H polarization and its subsequent transfer to non-equilibrium N(z) magnetization prior to (15)N photo-CIDNP laser irradiation. CHANCE-HSQC synergistically combines (1)H and (15)N photo-CIDNP

SUBMITTER: Sekhar A 

PROVIDER: S-EPMC2745520 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature