Figure 19.

Different interaction models of full-length Aβ_40/42 peptides with lipid membranes. (a) Aβ transmembrane pores with high Ca²⁺ permeability and selectivity.⁵⁷⁹ (b) Tetrameric Aβ₄₂ β-barrel pores in PC/PS/cholesterol/sphingomyelin and DPPC bilayers.⁵⁹¹ (c) Tetrameric Aβ₄₂ α-helix-bundle pores in a DPPC bilayer with Ca²⁺ transport across the bilayer.⁵⁹⁶ (d) Aβ₄₂ monomer with both α-helical and β-structure conformations being adsorbed on cholesterol-rich POPC bilayers, where increase of cholesterol promotes Aβ-membrane interactions and adsorption.⁶⁰³ (e) Aβ dimers on the GM1-clustering membrane, with C-terminal residues being inserted into the membrane.⁶⁰⁴ (f) Aβ tetramers with typical U-bent β-structure being preferentially adsorbed on and inserted into the POPE bilayer over the POPC bilayer, as driven by electrostatic interactions. (g) Aβ₄₂ pentamer being adsorbed onto a POPC/POPG bilayer via Ca²⁺ ionic bridges between Glu22 and Asp23 and anionic headgroups of the lipid bilayer.⁶¹⁰