[Study of the dynamic structure of globular proteins using impulse methods of nuclear magnetic resonance]

The data on the internal motion in the protein macromolecules and its relation to the function of various globular proteins which were obtained by studying the spin-lattice and spin-spin relaxation processes for the protein protons are reviewed. In dry proteins and polypeptides the types of the internal motion such as the methyl group rotation are observed which do not depend on free volumes within the globules. In the presence of water the oscillation motions of the molecular groups within the macromolecule are observed with frequencies lower 10(8) s-1 at negative temperatures and in the nanosecond range at room temperature. The rotation motions in serum albumin with frequencies 10(5)-10(6) S-1 and in RNAase with higher frequencies were registered. Comparative study of the spin-echo decay curves for protons of 7 enzymes and 5 non-enzymatic proteins, including the pair chymotrypsinogen-chymotrypsin, leads to the conclusion that more intense intermal motions occur in the enzyme macromolecules compared with nonenzymes. This conclusion corresponds to data achieved by other methods.