Dynamics of water in and around proteins characterized by ~1H-spin-lattice relaxometry [Caractérisation par relaxométrie spin-réseau des protons de la dynamique de l'eau à l'intérieur et autour des protéines]

摘要

Nuclear magnetic spin-lattice relaxation rate constants measured as a function of the magnetic field strength over wide ranges of Larmor frequency map the noise spectrum that drives spin relaxation. For water in and around protein systems, the spin relaxation reports on the average local translational mobility at the interface which is reduced by approximately factor of three from the bulk and there is anisotropy induced in the motions caused by the excluded volume created by the presence of the protein. Water also penetrates the protein and relatively few bound water sites provide a strong coupling between the protein dynamics and the water-proton-spin relaxation.