Beta-Amyloid (12-28), Human

Aβ (12–28) residues are the binding site for apolipoprotein E (apoE) on Aβ. This sequence encompasses a hydrophobic domain (residues 14–21) and a β-turn (residues 22–28) which place two hydrophobic domains of Aβ 14 to 21 and 29 to 40/42 opposite each other, allowing for the assembly of Aβ peptides into fibrils. The secondary structure of Aβ (12- 28), a neutral peptide, is dominated by a-helix and random coil. The interaction of apoE with residues 12 to 28 of Aβ is not just a non-specific hydrophobic interaction but plays a pivotal role in the mechanism of Aβ pathology in Alzheimer’s disease (AD). Aβ (11-28) and five other fragments enhanced aggregation of full length Aβ (1-40). All of the peptides that enhance aggregation contained either residues 17 to 20 or 30 to 35, indicating the importance of these regions for promoting aggregation of full-length Aβ.