Analysis of the mixed association between human apolipoproteins A-I and A-II in aqueous solution

The mixed association between two self-associating systems, human apolipoproteins A-I and A-II, has been evaluated by fluorescence spectroscopy and sedimentation equilibrium. The combined results are consistent with the formation of specific mixed oligomers between apolipoproteins A-I and A-II in aqueous solution. The data are discussed in terms of the role of protein-protein versus protein-lipid interactions in the quaternary organization of plasma lipoproteins.