 Bulk water molecules are also relatively far from magnetic field perturbing macromolecules, such that free water protons experience a more homogenous magnetic field, which results in slower transverse magnetization dephasing and a longer "T"2*.Conversely, hydration water molecules are mechanically constrained by extensive interactions with the local macromolecules and hence magnetic field inhomogeneities are not averaged out, which leads to broader resonance lines.This results in faster dephasing of the magnetization that produces the NMR signal and much shorter "T"2 values(<200 μs).