title: Biomolecular ligands screening using radiation damping difference WaterLOGSY spectroscopy.
abstract: Water-ligand observed via gradient spectroscopy (WaterLOGSY) is a widely used nuclear magnetic resonance method for ligand screening. The crucial procedure for the effectiveness of WaterLOGSY is selective excitation of the water resonance. The selective excitation is conventionally achieved by using long selective pulse, which causes partial saturation of the water magnetization leading to reduction of sensitivity, in addition to time consuming and error prone. Therefore, many improvements have been made to enhance the sensitivity and robustness of the method. Here we propose an alternative selective excitation scheme for WaterLOGSY by utilizing radiation damping effect. The pulse scheme starts simply with a hard inversion pulse, instead of selective pulse or pulse train, followed by a pulse field gradient to control the radiation damping effect. The rest parts of the pulse scheme are similar to conventional WaterLOGSY. When the gradient pulse is applied immediately after the inversion pulse, the radiation damping effect is suppressed, and all of the magnetization is inversed. When the gradient pulse and the inversion pulse are about 10-20 ms apart, the radiation damping effect remains active and drives the water magnetization toward +z-axis, resulting in selective non-inversion of the water magnetization. By taking the differences of the spectra obtained under these two conditions, one should get the result of WaterLOGSY. The method is demonstrated to be simple, robust and sensitive for ligand screening.
authors.affiliation: Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Sun
authors.forename: Xianwang
authors.initials: X
authors.lastname: Jiang
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.forename: Maili
authors.initials: M
authors.lastname: Liu
mesh_terms: D008024:Ligands; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008024:Ligands; D011506:Proteins