Kinetic and structural study of the interaction of myelin basic protein with dipalmitoylphosphatidylglycerol layers

The interaction of myelin basic protein (MBP) with: dipalmitoylphosphatidyl glycerol films has been investigated by means of a microgravimetric gauge s ensitive to the changes in load and structural modifications of the layer d eposited onto its surface. Fourier transform infrared spectroscopy, circula r dichroism, and x-ray diffraction have confirmed protein uptake by the lip id phase along with a global disordering effect onto the lipid alkyl chains and have shown a temporal evolution of the structure of water penetrating the lipid phase together with the protein. These effects are clearly relate d to the temporal variation of the microgravimetric gauge signal, Finally, measurements carried out on pre-annealed samples point out the role of meso scopic morphology in determining the pathways through which MBP penetrates the lipid multilayer. The results obtained in our model system could be use ful in clarifying the mechanisms of the myelinating and demyelinating proce sses that take place in the natural membrane.