Structural and functional characterization of human apolipoprotein e 72-166 peptides in both aqueous and lipid environments

Backgrounds. there are three apolipoprotein e (apoe) isoforms involved in human lipid homeostasis. in the present study,truncated apoe2-,apoe3- and apoe4-(72-166) peptides that are tailored to lack domain interactions are expressed and elucidated the structural and functional consequences. methods & results. circular dichroism analyses indicated that their secondary structure is still well organized. analytical ultracentrifugation analyses demonstrated that apoe-(72-166) produces more complicated species in pbs. all three isoforms were significantly dissociated in the presence of dihexanoylphosphatidylcholine. dimyristoylphosphatidylcholine turbidity clearance assay showed that apoe4-(72-166) maintains the highest lipid-binding capacity. finally,only apoe4-(72-166) still maintained significant ldl receptor binding ability. conclusions. overall,apoe4-(72-166) peptides displayed a higher lipid-binding and comparable receptor-binding ability as to full-length apoe. these findings provide the explanation of diverged functionality of truncated apoe isoforms. © 2011 hsieh and chou; licensee biomed central ltd.