Background: Role of apolipoprotein (apo) A-II on metabolism of high density lipoproteins (HDLs) is unknown.
Results: Conformational changes of apoA-I, the major apolipoprotein of HDL, caused by apoA-II in discoidal HDL are confined to two regions of apoA-I.
Conclusion: Interactions between the two major apolipoproteins in discoidal HDL are site specific.
Significance: Functional implications of HDL complexes will significantly benefit from such structural information.