Water in barnacle muscle. III. NMR studies of fresh fibers and membrane-damaged fibers equilibrated with selected solutes

摘要: Water in barnacle muscle has been studied using NMR techniques. Fresh fibers are compared with membrane-damaged treated solutes that greatly alter fixed charge and total water content. Both (97%) solute (3%) protons visible continuous wave spectra of oriented fresh fibers. No local field inhomogeneities were detected, nor cell significantly bound. In pulse experiments, all is exhibits a single exponential decay. fibers, T2 approximately or equal to 40 ms; faster decaying signals assigned immobile mobile on macromolecules. T1 T1p frequency dependent. Using equations derived for two-compartment model fast exchange, we calculate the following: tau b, correlation time anisotropic rotational motion bound water; Sb, its order parameter; ex, exchange between free fractions; f, fraction bound; Hr, grams per gram macromolecule. Whereas f varies inversely content, other parameters virtually constant, values: b 1.3 X 10(-8) S; ex 8 10(-6) s; Sb 0.06; Hr 0.1g H2O/g Thus, relaxation detectable properties macromolecules unaffected by macromolecular surface charge.