title: Signal enhancement for the sensitivity-limited solid state NMR experiments using a continuous, non-uniform acquisition scheme.
abstract: We describe a sampling scheme for the two-dimensional (2D) solid state NMR experiments, which can be readily applied to the sensitivity-limited samples. The sampling scheme utilizes continuous, non-uniform sampling profile for the indirect dimension, i.e. the acquisition number decreases as a function of the evolution time (t1) in the indirect dimension. For a beta amyloid (Aβ) fibril sample, we observed overall 40-50% signal enhancement by measuring the cross peak volume, while the cross peak linewidths remained comparable to the linewidths obtained by regular sampling and processing strategies. Both the linear and Gaussian decay functions for the acquisition numbers result in similar percentage of increment in signal. In addition, we demonstrated that this sampling approach can be applied with different dipolar recoupling approaches such as radiofrequency assisted diffusion (RAD) and finite-pulse radio-frequency-driven recoupling (fpRFDR). This sampling scheme is especially suitable for the sensitivity-limited samples which require long signal averaging for each t1 point, for instance the biological membrane proteins where only a small fraction of the sample is isotopically labeled.
authors.affiliation: Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 5, Room 406, Bethesda, MD 20892-0520, United States. qiangw@mail.nih.gov
authors.forename: Wei
authors.initials: W
authors.lastname: Qiang
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry; D002247:Carbon Isotopes; D003627:Data Interpretation, Statistical; D016014:Linear Models; D009210:Myofibrils / Q000737:chemistry; D009587:Nitrogen Isotopes; D016011:Normal Distribution; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D059629:Signal-To-Noise Ratio
chemical_list: D016229:Amyloid beta-Peptides; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes