FIGURE 2.

Screening and identification of cefoselis as a GRP78‐targeting agent. (A) BCL (1836) small molecule library was printed on the surface plasmon resonance (SPR) slide to screen the candidate GRP78‐targeting agent. (B) A total of 12 compounds were screened with the potential binding interaction. Cefoselis was identified as the strongest compound binding with GRP78 in a dose‐dependent manner. (C) Isothermal titration calorimetry (ITC) assay was performed to measure the binding affinity of cefoselis with the recombinant GRP78 protein. (D) The raw and integrated heat release in the ITC assay were fitted to obtain the binding parameters. (E) Cefoselis was covalently coupled to FITC (green), and GRP78 was labelled using Alexa Fluor 555 (red). The colocalisation of cefoselis and GRP78 in control or paclitaxel‐induced breast cancer cells was observed by immunofluorescence. (F) Cellular thermal shift assay (CETSA) of the thermal stability of the GRP78 in cell lysate after cefoselis (20 μM) treatment. ANOVA for repeated measurements was applied. ^* p < .05