Studies on the binding of plasma low density lipoproteins to arterial elastin

The mechanism of in vitro complex formation between plasma low density lipoproteins (LDL) and arterial elastin was studied. Rosette formation and decreased binding of the chemically modified LDL suggested that the intact protein moiety of lipoproteins was essential for the transfer of lipids from LDL to elastin. However, subsequent treatment of the elastin-LDL complex with trypsin removed the greater part of the lipoprotein protein but not the transferred cholesterol, indicating that the protein moiety of the lipoprotein did not take part in the retention of lipids on the elastin. In view of the observed effects of pH, ionic strength, various types of detergents and polarity of elastin preparations, it appears that the charged groups of the protein moiety of lipoproteins and the hydrophobicity of elastin proteins may play important parts in the binding of lipoproteins to arterial elastin.