UNAMBIGUOUS CORRELATIONS OF BACKBONE AMIDE AND ALIPHATIC GAMMA-RESONANCES IN DEUTERATED PROTEINS

Two 3D NMR pulse sequences that correlate aliphatic gamma carbon reson ance frequencies to amide proton and nitrogen chemical shifts in perde uterated proteins are presented. The HN(CO-CACB)CG provides only inter residue connectivities (NH(i) and C gamma((i-1))) while the HN(CACB)CG detects both the inter- and intraresidue (NH(i) and C-gamma(i) or Cga mma(i-1) correlations. These two experiments are useful for sequential assignments and the identification of residue type from the C-gamma s hifts. Spectra acquired on a perdeuterated 53-kDa protein illustrate t he sensitivity and utility of these experiments. (C) 1998 Academic Pre ss.