FIGURE 2.

Interchain interaction network stabilizing the parallel DFNKF oligomers. The DFNKF trimer is used here for demonstration. (a) Side-chain electrostatic interactions. The side-chain–side-chain hydrogen bonds and side-chain–N-/C-termini salt bridges include Asn–Asn, Asp– (N-termini), and Lys–COO⁻ (C-termini). The oxygen and nitrogen atoms on side chains forming the interchain hydrogen bonds are shown in red and blue balls, respectively. (b) Side-chain aromatic π-stacking. The end-to-end vectors of the DFNKF chains are perpendicular to the paper. The Phe aromatic rings are shown as large balls. It can be seen that the aromatic rings that stack onto each other are located at the two sides of the DFNFK β-sheet plane.