Fast Magic‐Angle Spinning 19 F NMR Spectroscopy of HIV‐1 Capsid Protein Assemblies

Abstract

19F NMR spectroscopy is an attractive and growing area of research with broad applications in biochemistry, chemical biology, medicinal chemistry, and materials science. We have explored fast magic angle spinning (MAS) 19F solid-state NMR spectroscopy in assemblies of HIV-1 capsid protein. Tryptophan residues with fluorine substitution at the 5-position of the indole ring were used as the reporters. The 19F chemical shifts for the five tryptophan residues are distinct, reflecting differences in their local environment. Spin-diffusion and radio-frequency-driven-recoupling experiments were performed at MAS frequencies of 35 kHz and 40–60 kHz, respectively. Fast MAS frequencies of 40–60 kHz are essential for consistently establishing 19F–19F correlations, yielding interatomic distances of the order of 20 Å. Our results demonstrate the potential of fast MAS 19F NMR spectroscopy for structural analysis in large biological assemblies.