Fig. 1

The structure characteristics of Y332D and the binding affinity of Y332D to TGF-β and VEGF. a Schematic representation of Y332D. Y332D is designed as a tetravalent and symmetric bispecific antibody that contains two anti-VEGF regions and two anti-TGF-β regions. The long chain of Y332D consists of five domains: VHb, CH1, CH2, CH3, VHH. The short chain of Y332D contains two domains: VLb, CL. The Fc region of Y332D is an engineered hybrid fragment: the CH2 domain is from IgG2, and the CH3 domain is from IgG1. b The non-reduced and reduced SDS-PAGE analysis of Y332D. Under nonreducing conditions, a single band was displayed. Two bands were observed under reducing conditions, representing the heavy and light chains. c, d The non-reduced and reduced CE-SDS analysis of Y332D. One peak was observed in the non-reduced CE-SDS, and two peaks were detected in the reduced CE-SDS. The purity of Y332D was more than 97%. e The results of SPR assay to detect the binding kinetics of Y332D to TGF-β1. f The results of SPR assay to detect the binding kinetics of Y332D to VEGFA. g The ELISA binding affinity of serially diluted Y332D or controls to plate-coated TGF-β1. h The ELISA binding affinity of serially diluted Y332D or controls to plate-coated VEGFA. i The simultaneous binding activity of Y332D to TGF-β1 and VEGFA by ELISA. Serially diluted Y332D or controls were incubated with plate-coated TGF-β1. Then, VEGFA-Biotin and peroxidase-conjugated streptavidin were added sequentially. Bars, SDs