His-tagged Protein Fragment Binding Assay

VERO-E6 and BEAS-2B cells were digested with 0.25% trypsin. Next, 1.5 × 10⁵ cells were incubated with His-tagged protein fragments at 0.25 μM for 1 h at 37 °C, except for the control groups. The cells were then washed and stained with PE anti-His Tag antibody (Biolegend, San Diego, USA) for 1 h at 4 °C. The cells were further washed and resuspended, subjected to flow cytometry analysis. A total of 20,000 events were acquired for each sample using the BD FACSVerse™ system (Becton Dickinson, Franklin Lakes, NJ)^{39 (link)–42 (link)}. Data were analyzed by FlowJo software (Version 10.5.3, Tree Star Software; CA, USA) as described previously^{43 (link)}.