Analysis of apolipoproteins and lipoproteins by capillary electrophoresis

Capillary electrophoresis provides a valuable analytical tool for the analysis of apolipoproteins and lipoproteins. Sodium dodecyl sulfate (SDS) capillary gel electrophoresis can resolve human and animal apolipoprotein (apo) A-I, apo A-II, apo E and apo A-IV in isolated high density lipoproteins (HDLs) and is capable of analysing HDL apo A-I and apo A-II content with a coefficient of variation (CV) of less than 5%. Capillary zone electrophoresis (CZE) using coated capillaries with Tricine-urea buffer can also be used for the analysis of HDL apolipoproteins and is also capable of resolving apo A-I isoforms, pro-apo A-I, mature apo A-I and deamidated apo A-I. Furthermore it can separate human A-I from endogenous rabbit A-I in transgenic rabbits expressing the human apo A-I gene. Capillary isoelectric focusing can also separate apo A-I isoforms. Analysis of charge-modified low density lipoprotein (LDL) (ox-LDL) produced by in vitro lipid peroxidation can be performed by CZE and the technique can be used to monitor simultaneous changes in the electrophoretic mobility and absorption spectra of LDL.