Backbone assignments in solid-state proteins using J-based 3D Heteronuclear correlation spectroscopy

3D NCACO, NCOCA, and CANCO scalar-coupling driven correlation experiments are presented for protein backbone assignments in the solid-state. These I -MAS experiments show superior resolution in the indirect dimensions through the elimination of heteronuclear and homonuclear couplings and enhanced sensitivity, which allow us to trace out the entire protein backbone for G131. Our results demonstrate that scalar-based methods are sufficiently well-developed to serve as a complementary tool to dipolar methods, which will be especially useful for assignment of large proteins, where resonance overlap presents a major challenge to solid-state NMR.