AN APPROACH TO GLOBAL FOLD DETERMINATION USING LIMITED NMR DATA FROM LARGER PROTEINS SELECTIVELY PROTONATED AT SPECIFIC RESIDUE TYPES

A combination of calculation and experiment is used to demonstrate tha t the global fold of larger proteins can be rapidly determined using l imited NMR data, The approach involves a combination of heteronuclear triple resonance NMR experiments with protonation of selected residue types in an otherwise completely deuterated protein, This method of la belling produces proteins with alpha-specific deuteration in the proto nated residues, and the results suggest that this will improve the sen sitivity of experiments involving correlation of side-chain (H-1 and C -13) and backbone (H-1 and N-15) amide resonances. It will allow the r apid assignment of backbone resonances with high sensitivity and the d etermination of a reasonable structural model of a protein based on li mited NOE restraints. an application that is of increasing importance as data from the large number of genome sequencing projects accumulate s, The method that we propose should also be of utility in extending t he use of NMR spectroscopy to determine the structures of larger prote ins.