[Study of the function of multienzyme systems of Escherichia coli cellular structures in organic media microemulsions by (31)P-NMR and spin probing].
Dynamics of substrate pools and level of inorganic phosphate P(i) in the course of glucose-6-phosphate (G6P) utilization by Escherichia coli have been studied by 31P NMR and EPR methods on cells immobilised in a three component water-in-oil microemulsion composed from tridecane, nonionic surfactant Tween 81 and a low amount of water. The state of the electron transport chain in cell membranes has been evaluated on the basis of reduction rates of exogenous nitroxide radicals. Low water activity a(w) in the external microemulsion appears to inhibit, to some extent, glycolytic enzymes and electron transport proteins in the membrane structures without disturbing the membrane integrity and solubilization of lipoproteins in reverse micelles. Enzyme activity has been restricted by the micellar substrate diffusion and by decrease in water activity a(w) in the course of the extensive molecular interchange of bound water between the external microemulsion phase and the internal cell structures.
B P
BP
Nikolaev
D K
DK
Toropov
A M
AM
Shliakov
D004058:Diffusion; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D004655:Emulsions; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006019:Glycolysis; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism
D004655:Emulsions; D005958:Glucosephosphates; D008823:Micelles; D009097:Multienzyme Complexes; D019298:Glucose-6-Phosphate