Fig. 2: Target binding of NC-Cow1 Fab wt and variants with swapped ulCDR.

a–h Kinetic measurements of Fab fragments against their respective antigens (HIV Env trimer for wt and var1 as well as Δknob, human EGFR for var2, var3 and var4, human Nkp30 for var5 and var6). The antigen binding was measured at different Fab concentrations (50, 100, 500, 1000 nM for wt, var 3 and var4. 100, 200, 500, 1000 nM for var1. 1000 nM for Δknob. 25, 50, 100, 500 nM for var2, var5, and var6.) and fitting functions (in red color) were calculated with the BLItz software. i–p Molecular mass and eluting peaks in SEC-MALS for Fab variants (black), their corresponding antigens (green), and Fab/antigen mixtures (red). Samples with Fab and HIV Env trimer were mixed in a 3:1 ratio, while the samples with Fab and EGFR or Nkp30 were mixed in a 1:1 ratio.