Interaction of heparin with low density lipoproteins. Formation of soluble high molecular weight complexes.

The electrophoretic pattern of low density protein (LDL) in heparinized human serum was analyzed by means of molecular-sieve electrophoresis in polyacrylamide gradient gels. While increasing the electrophoretic mobility of LDL in nonsieving gels (agarose), heparin markedly decreases the electrophoretic mobility of LDL in polyacrylamide gels. This slowing down reflects the formation of large polymers where individual lipoprotein molecules are linked by heparin bridges.