Extended Data Fig. 6: Antibody-peptide inhibitor conjugates (APIC) characterization.
From: Antibody–peptide conjugates deliver covalent inhibitors blocking oncogenic cathepsins
a) Intact mass spectrometry analysis of the αCD22-C10 APIC (black peaks) compared to the unconjugated αCD22 antibody (red peaks). b) Mass photometry analyses of CTSS, αCD79 antibody or αCD79-C10 APIC alone or incubated together. APIC conjugated with a 2-fold, 4-fold or 8-fold molar excess of C10-NNPI was used. CTSS was always used in 10-fold molar excess to antibody or APIC. Histograms represented in Fig. 2c were obtained by overlaying data from this experiment. c, d) Flow cytometry analysis of CD22 (c) and HER2 (d) surface receptor expression in different B cell lymphoma (WSU-DLCL2, SU-DHL-4, Raji, Ly-19), breast cancer (HCC-1569, BT-474) and bladder cancer (RT-4) cell lines. One representative histogram per cell line is shown (n = 2 per cell line). e) Flow cytometry analysis of SU-DHL-4 lymphoma cells stained with AF-488 labeled APIC. An anti-AF-488 antibody was used to quench the signal of the fluorophore and assess the internalization of the APIC at 4 °C and 37 °C (n = 2 per condition).
