Efficient spin-spin scalar coupling mediated C-13 homonuclear polarization transfer in biological solids without proton decoupling

We demonstrate that an efficient C′↔Cα polarization transfer based on J-coupling can be realized under fast magic-angle spinning (MAS) condition without 1H decoupling. Experimental results are presented for model crystalline compounds as well as a non-crystalline 17-residue polypeptide MB(i+4)EK. Measurements on MB(i+4)EK demonstrate that 53% of the initial C′ polarization was transferred to the cross peaks at 7.05 T under 25 kHz MAS spinning.