In Silico Analysis of the Apolipoprotein E and the Amyloid β Peptide Interaction: Misfolding Induced by Frustration of the Salt Bridge Network
Figure 2
Distance analysis between Aβ and ApoE residues involved in the electrostatic interactions during the ApoE-Aβ complex formation.
The structure plotted corresponds to the ApoE4-Aβ complex (color code blue and golden, respectively). Aβ residues are indicated by underlined and italics characters. Aβ peptide residues from Gly25 to Val40 have been removed for a clearer representation. The sub index for the ApoE4 residues indicates helix location. The green dotted line depicts the salt bridge network between residues of the Aβ peptide and ApoE4 and between residues in the ApoE4 helices I and II. (A) Distance variation during the 10 ns MD simulation for the Aβ Asp23 and the ApoE4 Arg38 electrostatic pair (black) and the Aβ Asp1 and the ApoE4 Arg142 electrostatic pair (grey). (B) Distance variation during the 10 ns MD simulation for the Asp35-Arg38 electrostatic pair, for ApoE4 alone (grey) and for ApoE4-Aβ (black). (C) Distance variation during the 10 ns MD simulation for the Arg32-Asp35 electrostatic pair, for ApoE4 alone (grey) and for ApoE4-Aβ (black). (D) Distance variation during the 10 ns MD simulation for the Arg32-Glu66 electrostatic pair, for ApoE4 alone (grey) and for ApoE4-Aβ (black). In all plots the salt bridge thresholds of 4.3 and 7.0 Å are indicated by dashed lines. Selected residues have been represented as ball and sticks and colored by element (C, grey; O, red; N, blue).