Longitudinal Spin Order Labeling on Multiple Quantum Coherences Enables NMR Analysis of Intrinsically Disordered Proteins at Ultrahigh Resolution

Abstract

Intrinsically disordered proteins (IDPs) play an important role in cell signaling, and NMR is well-suited to study conformational ensembles and dynamics of IDPs. However, the intrinsic flexibility of IDPs often results in severe spectral overlap, which hampers accurate NMR data analysis. By labeling the longitudinal spin order of an α proton (i.e., Hα z ) on multiple quantum coherences of backbone nuclei (e.g., N y C′ x Cα y ), we were able to apply pre-homonuclear decoupling (PHD) to transverse relaxation-optimized spectroscopy (TROSY). The proposed scheme provides ultrahigh resolution in both amide proton and nitrogen dimensions, as illustrated in the analysis of Tau and alpha-synuclein (α-Syn) proteins. The PHD-TROSY readout enabled complete backbone resonance assignment of α-Syn using a single 3D HNCA experiment performed on a 600 MHz NMR spectrometer.

Precisely predicting the 1H and 13C NMR chemical shifts in new types of nerve agents and building spectra database

“…In addition, as exposure to the nerve agent cannot be detected based on color or smell, the development of an appropriate detection method and a framework for the short-term storage of such data is also essential. Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful tools for the detection and characterization of unknown materials as it is widely used for structural elucidation as well as qualitative and quantitative analysis of hazardous materials 7 – 9 . In spite of its dependence on mixture analysis, NMR spectroscopy exhibits several advantages over other detection methods: it is non-destructive, no standards are necessary for quantification, and it expresses chemical shifts and coupling constants as functions of the nucleus and its environment 8 , 9 .…”

“…Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful tools for the detection and characterization of unknown materials as it is widely used for structural elucidation as well as qualitative and quantitative analysis of hazardous materials 7 – 9 . In spite of its dependence on mixture analysis, NMR spectroscopy exhibits several advantages over other detection methods: it is non-destructive, no standards are necessary for quantification, and it expresses chemical shifts and coupling constants as functions of the nucleus and its environment 8 , 9 . However, the practical application of NMR-based analytical and structural methods for the detection and analysis of nerve agents is severely limited by the risk of exposure to highly toxic Novichok agents 10 .…”