Measurement of one-bond 1Hα-13Cα couplings in backbone-labelled proteins

NMR dipole-dipole couplings between protein backbone nuclei (H-1(alpha), C-13(alpha), N-15, H-1(N),C-13') offer enormous scope for the rapid determination of protein global folds. Here, we show that measurement of one-bond splittings in the protein backbone is facilitated by use of protein that is selectively isotopically enriched only in the backbone atoms. In particular, H-1(alpha)-C-13(alpha) couplings can be measured simply and with high sensitivity by use of conventional heteronuclear single quantum correlation (HSQC) techniques.