Fig. 1.

Model of domain interaction as a determinant of conformation of apoE. In apoE4 (left), Arg-112 orients the side chain of Arg-61 into the aqueous environment where it can interact with Glu-255, resulting in interaction between the amino- and carboxyl-terminal domains. In apoE3 (right), Arg-61 is not available to interact with residues in the carboxyl-terminal domain, resulting in a very different overall conformation