Data from: A nuclear magnetic resonance study of water in aggrecan solutions

Aggrecan, a highly charged macromolecule found in articular cartilage, was
investigated in aqueous salt solutions with proton nuclear magnetic
resonance. The longitudinal and transverse relaxation rates were
determined at two different field strengths, 9.4 T and 0.5 T, for a range
of temperatures and aggrecan concentrations. The diffusion coefficients of
the water molecules were also measured as a function of temperature and
aggrecan concentration, using a pulsed field gradient technique at 9.4 T.
Assuming an Arrhenius relationship, the activation energies for the
various relaxation processes and the translational motion of the water
molecules were determined from temperature dependencies as a function of
aggrecan concentration in the range 0–5.3% w/w. The longitudinal
relaxation rate and inverse diffusion coefficient were approximately
equally dependent on concentration and only increased by upto 20% from
that of the salt solution. The transverse relaxation rate at high field
demonstrated greatest concentration dependence, changing by an order of
magnitude across the concentration range examined. We attribute this
primarily to chemical exchange. Activation energies appeared to be
approximately independent of aggrecan concentration, except for that of
the low-field transverse relaxation rate, which decreased with
concentration.