Figure 1.

(A) Schematic of AFM experimental configuration. Space-filling models of fibrin fragment desAB-NDSK and fibrinogen colored by polypeptide chains α, β, and γ, and available in an online version of the article. The formation of an ‘A-a’ bond (circled) is shown between the γ-module of fibrinogen and knob ‘A’ of the desAB-NDSK fragment (dashed line). Knob ‘A’ (dashed line) does not appear in crystal structures and is thus approximated. Fibrin(ogen) knob ‘B’ and αC domains are not shown. (B) Detailed representation of ‘A-a’ bond showing fibrinogen D region (ribbons) with bound GPRP peptide (spheres). The GPRP peptide is knob ‘A’ peptide-mimetic. The following Protein Data Bank entries were used to generate protein models: 3GHG (fibrinogen), 2A45 (desAB-NDSK), 1BJ5 (BSA), and 1LTJ (fibrinogen D region with bound knob ‘A’). Scheme is not to scale. Protein models were generated with Pymol (DeLano Scientific, Palo Alto, CA).