Figure 4.

The structure and antigen binding is not perturbed by the Ser85Cys mutation. (a) Overlay of the 16 different Nb36 molecules present in the four different crystals, with CDR1, CDR2 and CDR3 coloured red, green and yellow, respectively. (b) Structural superposition of native Nb36-Nat1 (light blue) and PCMB-labelled Nb36-C85-1 (dark blue). (c, d) Binding of the C5 antigen to immobilized native Nb36 or PCMB-labelled Nb36-C85 measured by biolayer interferometry. The experimental association and dissociation curves are shown in black and the fitted curves are shown in blue.