Fig. 2

The affinity of anti-CTGF scFv B2 increased after mutagenesis and reconstruction to the IgG1 format. (A) The number of eluted phages. After three rounds of screening for CTGF in phage-displayed scFv library with scFv B2-V_H-CDR3 mutagenesis, the number of eluted phages increased 163-fold over that of the first round. (B) Amino acids of the heavy and light chain variable region of scFv B2 and mut-scFv B2. The red letters indicate residues that vary between scFv B2 and mut-scFv B2. Underline: CDR1, CDR2, CDR3 regions of heavy and light chain. (C) Affinity of scFv B2 and mut-scFv B2 determined by surface plasmon resonance (SPR). (D) Inhibition rate of CTGF-induced cell proliferation. Cell viability of HUVECs was evaluated by CCK-8 assay after treated with recombinant human CTGF (50 nM) and scFv B2 or mut-scFv B2 (1-500 nM) for 8 h. HUVECs only treated with CTGF (white dot) were used as control. Formula used to calculate the inhibition rate is shown in Methods. (E) Affinity of IgG mut-B2 determined by SPR.