Figure 4
Bioactivity and affinity of TNFRII-Trimer and TNFRII-Fc to TNF-α. (a) Bioactivity detection of TNFRII-Trimer and TNFRII-Fc. Neutralizing TNF-α induced-cytotoxicity assays were performed using L929 cell line, and cell viability was evaluated using a colorimetric MTT assay. The IC50 value of TNFRII-Trimer and TNFRII-Fc is 54pM and 98.6pM, respectively. (b) Ligand binding kinetics of TNFRII-Trimer and TNFRII-Fc binding to TNF-α were assessed by biolayer interferometry measurements. The Super Streptavidin biosensor tips of the ForteBio Octet RED 96 were coated with biotinylated TNFRII receptors. The biosensor tips were dipped in increasing concentrations gradient of the same molarity (2.5 nM–39 nM) to measure binding of TNFRII-Trimer and TNFRII-Fc to TNF-α and subsequently moved to wells containing buffer (PBS) to measure dissociation rates. Detailed results were shown in Table 2.
