Journal of Lipid Research, Vol 25, 86-91, Copyright © 1984 by Lipid Research, Inc.
Isolation and characterization of polymorphic forms of porcine apoC-II by chromatofocusing
G Knipping, E Steyrer, R Zechner and A Holasek
Chromatofocusing, which separates proteins on the basis of their different
isoelectric points, was used to isolate isoforms of apoC-II from porcine
very low density lipoproteins. This method was found to be time-saving and
the yield of protein recovery was high. With chromatofocusing, three
polypeptides were obtained which were characterized by amino acid analysis,
double immunodiffusion, and by their ability to activate bovine milk
lipoprotein lipase. The three polypeptides had the same amino acid
composition, gave a reaction of identity against a monospecific antiserum
to porcine apoC-II, but had different isoelectric points between pH 4.8 and
4.4. They all enhanced the activity of lipoprotein lipase, but to a lesser
degree than native porcine serum. There was no indication of the existence
of apolipoproteins that correspond to human apoC-III polypeptides.