[Increase of the water content in the lipid phase of lipoproteins during peroxidation]

By means of fluorescent probes of pyrene and 4-dimethylaminochalcone (DMC) an increase of polarity of the lipid phase of lipoproteins of low density LDL during their autooxidation was discovered. The observed change of polarity is explained by the penetration of water molecules into the LDL phospholipid layer, which form hydrogen bonds with polar groups resulting from the peroxidation of lipids. Such "water corrosion" of the membranes is suggested to bring about a change of matrix properties of the phospholipid layer, particularly a change in LDL protein conformation discovered earlier during peroxidation.