Effects of cations on dipalmitoyl phosphatidylcholine/cholesterol/water systems

The structural diversity of DNA–neutral phospholipids–divalent metal cations aggregates: a small-angle synchrotron X-ray diffraction study

“…) spontaneously form vesicles with a positive surface charge (Akashi et al, 1998;Inoko et al, 1975). The formation of large light scattering aggregates due to the interaction of polynucleotides with phosphatidylcholine vesicles in presence of Mg 2+ ions was documented more than two decades ago (Budker et al, 1978).…”

Structures of uranyl-decorated lecithin and lecithin–cholesterol bilayers

“…As was demonstrated by Inoko et al (1975), the bound uranyl ions cause repulsive forces between membranes, and inter-membrane distances seem to be very large (presumably more than 150 A~) in the dispersion. Therefore, effects of inter-membrane interferences (if there are such interferences) should appear mainly at very low angles.…”

“…Shah & Schulman (1967) studied the ionic structure ofdipalmitoyl lecithin monolayers and proposed that one Ca 2+ ion binds to two phosphate groups. Inoko et al (1975) showed that cholesterol prevents the binding of Ca 2+ ions to dipalmitoyl lecithin. The mode of UO 2+ binding seems to be quite different from the case of Ca 2+.…”

“…The observations described in the Experimental suggest that this bump is a contribution from the scattered intensity in the vicinity of the X-Y plane in reciprocal space. As discussed by Inoko et al (1975), the hexagonal unit cell usually assigned to the lipid membrane [a~4.2. (2/I/3 ) A] contains half a molecular unit of the head group.…”

“…Recently we have shown that adding a very small amount of uranyl acetate to the dipalmitoyl lecithinwater system destroys the lamellar phase and results in dispersion of lecithin membranes (Inoko, Yamaguchi, Furuya & Mitsui, 1975). During the experiments we found that the dispersions of lecithin and lecithincholesterol membranes decorated by about equimolar uranyl acetate gave very distinct continuous X-ray diffraction patterns.…”