[Surface of a human low-density plasma lipoprotein: areas occupied by proteins and lipids]

The distribution pattern of the protein on the surface of low density lipoproteins (LDL) of blood plasma was studied by quantitative estimation of the efficiency of the inductive-resonance energy transfer between the fluorescent probes and between the proteins and probes. The fluorescent probes used were 4-dimethyl-aminochalcone, 6-(2-anthroyl)-hexane acid and 7-(2-anthryl)-heptane acid. The lipids and proteins were found to occupy approximately equal areas on the LDL surface. The average area of the protein layer on the surface of one LDL particle made up to 480 +/- 60 nm2, the layer width was about 1 nm. The protein was rather evenly distributed on th surface of LDL particle without forming large (diameter much greater than 4 nm) plaques.