Showing papers by "B. de Kruijff published in 1984"
TL;DR: It is proposed that endogenous RNA present in mitochondria and mitoplasts is not accessible for adriamycin at low concentrations of the drug due to the presence of an intact lipid barrier, and the evidence for the potential importance of RNA as a target comes from experiments on outer membranes and microsomes.
82 citations
01 Jan 1984
TL;DR: This proposition is strongly supported by model membrane experiments in which it has been demonstrated that factors such as Ca2+ and temperature, which trigger the transition from bilayer to hexagonal II phase, in fact induce membrane fusion.
Abstract: Membrane fusion is an ubiquitous event in cell biology. One can distinguish two types of fusion: (i) outside/outside fusion, for example endocytosis, and (ii) inside/inside fusion, for example exocytosis. In spite of this difference in types of fusion in relation to membrane asymmetry and in spite of the large variety of lipid compositions encountered in biological membranes, a universal mechanism can be postulated for the role of lipids in membrane fusion. In this concept the lipids leave the bilayer configuration temporarily and locally. This notion, and the fact that any biological membrane contains a substantial amount of lipids which prefer the non-bilayer hexagonal II phase in physiological conditions, has led to the hypothesis that such hexagonal II phase lipids play a crucial role in membrane fusion. This proposition is strongly supported by model membrane experiments in which it has been demonstrated that factors such as Ca2+ and temperature, which trigger the transition from bilayer to hexagonal II phase, in fact induce membrane fusion.
60 citations
TL;DR: The experiments demonstrate that apocytochrome c is able to pass a lipid barrier and this process shows both a lipid- and protein specificity.
57 citations
TL;DR: The results show that egg-PE is more sensitive to the effects of peroxidation than egg-PC, and strongly influenced the polymorphic phase behavior of PE.
Abstract: The influence of oxygen-induced phospholipid peroxidation on the phase behavior of aqueous dispersions of both egg phosphatidylcholine (egg-PC) and egg phosphatidylethanolamine (egg-PE) has been investigated. Phospholipid peroxidation was followed via malondialdehyde formation and analyses of acyl chain compositions. 13C nuclear magnetic resonance spectroscopy (NMR) and the amino-indicating probe trinitrobenzenesulfonic acid were used to study the effect of peroxidation on the chemical structure of hydrated egg-PE. The macroscopic organization of the phospholipids was monitored by 31P NMR and small-angle X-ray diffraction. Differential scanning calorimetry was employed to study the influence of peroxidation on the thermotropic behavior of egg-PE. The results show that egg-PE is more sensitive to the effects of peroxidation than egg-PC. In the latter, no changes in the macromolecular organization were observed. However, peroxidation strongly influenced the polymorphic phase behavior of PE. Initial peroxidation stabilized hydrated egg-PE in a lamellar system up to 70 degrees C, presumably by modification of the head group. Such modifications were confirmed by 13C NMR experiments, which indicated the formation of Schiff bases between PE head groups and aldehydes. Furthermore, quantitative analyses of trinitrobenzenesulfonic acid reactable egg-PE and the corresponding fatty acid compositions revealed the presence of cross-links between the ethanolamine head groups, likely involving the bifunctional malondialdehyde. Prolonged peroxidation of egg-PE resulted in a loss of order in the system, possibly by the formation of intermediate nonbilayer structures.
52 citations
TL;DR: The results suggest that the nonspecific permeability of the band 3-lipid vesicle is strongly lipid-dependent, and increase in specific anion permeability expected as a consequence of the presence of band 3 in the erythrocyte lipid vesicles was found to be very limited.
19 citations
TL;DR: Glycophorin was incorporated into large unilamellar vesicles and the bilayer permeability was measured as a function of the lipid composition and variations in the polar headgroups by incorporation of DOPE, DOPS and, to a lesser extent, cholesterol restored the barrier function.
17 citations