title: Sensitivity enhancement in (HCA)CONH experiments.
abstract: A novel sensitivity-enhancement technique is proposed for experiments which correlate protein backbone resonances and start with magnetization from 13Calpha-1Halpha groups. The technique is based on replenishing magnetization lost by dipole-CSA cross-correlated relaxation of the 13Calpha spin with 13Calpha steady state magnetization. The principle is demonstrated for the (HCA)CONH experiment, resulting in 1.6-fold sensitivity enhancement compared to the HN(CA)CO experiment. Furthermore, other versions of the (HCA)CONH experiment were evaluated, including a novel experiment with spin-locking of transverse 13C-1H two-spin coherence, and a cross-correlation compensated (CA)CONH experiment which starts from 13C rather than 1H magnetization.
authors.affiliation: Structural Chemistry Laboratory, AstraZeneca R&D Mölndal, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Folmer
authors.forename: G
authors.initials: G
authors.lastname: Otting
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry*; D016969:Desulfovibrio vulgaris / Q000737:chemistry; D005420:Flavoproteins; D006863:Hydrogen-Ion Concentration; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D014452:Ubiquitins / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C086046:FMN-binding protein, Desulfovibrio vulgaris; D005420:Flavoproteins; D014452:Ubiquitins