Interaction of Triton X-100 and octyl glucoside with liposomal membranes at sublytic and lytic concentrations. Spectroscopic studies.

The molecular mechanism of the solubilisation of phospholipid bilayers by nonionic detergents was studied by turbidity changes, carboxyfluorescein fluorescence dequenching, steady-state and time-resolved fluorescence anisotropy of DPH, lifetime measurements, ANS binding and 31P-NMR. Particular attention has been paid to the effective detergent-to-lipid ratio in the lipid phase. The disturbance of the bilayer arrangement varies considerably for various detergents depending on the hydrophilic and lipophilic parts of the molecule. Small amounts of detergents with low CMC (e.g. Triton X-100) can even induce an optimisation of packing of the lipid molecules.