TABLE 2.

Central region electrostatic interactions involving side chains E22 and D23. Highly populated interactions involving the side chains of E22 and D23 in the central region are listed here. Listed populations represent average bond frequencies for equivalent atoms in the side chain (for example, “ASP23O_γ” is the average of interactions involving the ASP23O_γ1 and ASP23O_γ2 atoms).

Donor – Acceptor Atoms	% in Aβ42 Ensemble	% in Aβ40 Ensemble	% in Aβ42-M35ox Ensemble
Hydrogen Bonds
VAL24HN – ASP23Oγ	27.70	31.71	24.87
GLY25HN – ASP23Oγ	56.61	61.15	50.93
SER26HN – ASP23Oγ	58.69	65.38	53.56
SER26HOγ – ASP23Oγ	32.43	32.43	37.29
ASN27HN – ASP23Oγ	31.43	36.00	29.41
LYS28HN – ASP23Oγ	17.41	24.69	17.68
Salt Bridges
LYS28Hζ – GLU22Oδ	9.03	20.26	17.52
LYS28Hζ – ASP23Oγ	3.67	2.25	4.25