title: NOESY-WaterControl: a new NOESY sequence for the observation of under-water protein resonances.
abstract: Highly selective and efficient water signal suppression is indispensable in biomolecular 2D nuclear Overhauser effect spectroscopy (NOESY) experiments. However, the application of conventional water suppression schemes can cause a significant or complete loss of the biomolecular resonances at and around the water chemical shift (ω2). In this study, a new sequence, NOESY-WaterControl, was developed to address this issue. The new sequence was tested on lysozyme and bovine pancreatic trypsin inhibitor (BPTI), demonstrating its efficiency in both water suppression and, more excitingly, preserving water-proximate biomolecular resonances in ω2. The 2D NOESY maps obtained using the new sequence thus provide more information than the maps obtained with conventional water suppression, thereby lessening the number of experiments needed to complete resonance assignments of biomolecules. The 2D NOESY-WaterControl map of BPTI showed strong bound water and exchangeable proton signals in ω1but these signals were absent in ω2, indicating the possibility of using the new sequence to discriminate bound water and exchangeable proton resonances from non-labile proton resonances with similar chemical shifts to water.
authors.affiliation: Nanoscale Organisation and Dynamics Group, School of Science and Health, Western Sydney University, Penrith, NSW, 2751, Australia.
authors.forename: Allan M
authors.initials: AM
authors.lastname: Torres
authors.affiliation: Nanoscale Organisation and Dynamics Group, School of Science and Health, Western Sydney University, Penrith, NSW, 2751, Australia. g.zheng@westernsydney.edu.au.
authors.forename: Gang
authors.identifier: 0000-0002-5721-4072
authors.initials: G
authors.lastname: Zheng
authors.affiliation: Nanoscale Organisation and Dynamics Group, School of Science and Health, Western Sydney University, Penrith, NSW, 2751, Australia.
authors.forename: William S
authors.initials: WS
authors.lastname: Price
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009113:Muramidase / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D011506:Proteins; D014867:Water; D009113:Muramidase
keywords: Biomolecule; Diffusion; NMR; NOESY; PGSE; Protein NMR; Solvent signal suppression; Stimulated echo