2.

Collagen chain registration and surface heterogeneity. (A) Schematic of three artificial collagen chains composed of simple Gly-X-Y repeats. Glycine (G) is shown in black, and the X and Y positions are color-coded by residue type to highlight positional differences. (B) Six theoretically possible chain registrations for the three artificial collagen chains shown in panel (A). L, M, and T indicate Leading, Middle, and Trailing positions within the triple helix, respectively. (C) Selected region is highlighted with color blocks, and the magnified segment is boxed in red. (D) Schematic representation of the surface patterns generated by the six different chain registrations shown in panel (B), focusing on the segment annotated in panel (C). White line indicates the potential formation of an electrostatic interaction between the lysine (K) and aspartic acid (D) residues.