Partitioning of high-density lipoproteins in charge-sensitive two-phase systems.

Aqueous polymer two-phase systems characterized by a difference in the electrical potential between the upper and the lower phase (charged systems) are useful tools for the detection of changes in the surface charge and hydrophobicity of high-density lipoproteins (HDL). While the large particle size of low-density lipoproteins (LDL) leads to accumulation at the interface, the smaller diameter and the higher surface charge density of the native HDL particles allows partitioning without aggregation at the interface. Charged two-phase systems can be used to check the native state of HDL samples. Moreover, these systems would be suitable for investigating the hydrophobicity and surface charge of modified HDL.