PULSED-FIELD GRADIENT NMR AND NUCLEAR MAGNETIC-RELAXATION STUDIES OF WATER MOBILITY IN HYDRATED COLLAGEN-II

Transverse nuclear magnetic relaxation and self-diffusion of water wer e measured in hydrated collagen II. Self-diffusion measurements were c onducted by pulsed field gradient NMR (PFG NMR) and weighting of the d ifferent species in the signal by variable T-2 relaxation in the exper iment. Two fractions of water protons were detected, one with a short T-2 value but high diffusivity and one with a long T-2 value and low, completely restricted diffusion. The distance of the diffusion barrier s was determined to be 2.3 mu m. Possible reasons for the restriction in the movement of the water molecules in comparison with structural m odels of collagen II are discussed.