MULTIPLE-QUANTUM FILTERED O-17 AND NA-23 NMR ANALYSIS OF MITOCHONDRIAL SUSPENSIONS

The fraction of strongly- and weakly-bound water molecules within mito chondrial suspensions, determined using three-quantum filtered O-17 NM R relaxation analysis, was found to be large in comparison with that i n erythrocytes and concentrated solutions of bovine serum albumen. It is suggested that bound water, together with regulation of mitochondri al matrix volume, may be an important controlling factor in the modula tion of enzymic activity in the matrix. A spin I = 5/2 Jeener-Broekaer t experiment and a four-quantum filtration experiment were used to dem onstrate the absence of orientationally ordered water molecules within the mitochondrion, In contrast, the mitochondrial sodium environment was shown to be highly ordered using a spin I = 3/2 Jeener-Broekaert e xperiment. (C) 1998 Elsevier Science B.V. All rights reserved.