220 - Mixed films of a structural myelin protein and an acidic phospholipid

Mixed monolayers of the apoprotein A of Folch-Lee proteolipid from the central nervous system myelin and phosphatidyl-inositol monophosphate L from wheat germ have been spread on aqueous NaCl 10 −2 M and pH = 5.5 substrates at room temperature. The ratio [A]/[L] was varied and its effect on the surface pressure and potential of the films as well as on Ca 2+ binding by them were studied (Part II). The model put forward for A in a previous study 11 to interpret the surface potential measurement results was extended to the presently studied system A + L to include the presence of the phospholipid phosphate groups. The theoretical approach worked out previously 11 has been improved. A complementary boundary condition is added, which allows for coupling between the electrical field originating in the permanent dipole moments of the mixed films constituents and the space distribution of the mobile ions.