Nuclear magnetic resonance of E. coli ribosomes and viruses.

1H Nuclear Magnetic Resonance spectra of a number of viruses and E. Coli ribosomes revealed that experimental values of the linewidth (πT2)−1 (< 320 Hz) and T1 (< 1 sec) of the observable nuclei are too small to be accounted for by the system's molecular weight. The nuclei therefore must be internally mobile. From 13C Nuclear Magnetic Resonance spectra of 12% 13C enriched E. Coli ribosomes, it follows that 30% of the 5000 CH2CH3 groups, 10–20% of the 225 Phe residues, 20% of the δ-Arg and β-Lys carbons, ∼ 100 nucleotides and a number of Cα carbons are internally mobile. It is demonstrated that 13C Nuclear Magnetic Resonance can fruitfully be applied to intact ribosomes.