Fig. 8
a-c Cytotoxicity of trastuzumab-PE24 on (a) HCC1954 (Her2 positive), (b) MDA-MB-453 (Her2 positive), and (c) MDA-MB-231 (Her2 negative). Cell viability was measured by the WST-8 assay. The IC50 of trastuzumab-PE24 for HCC1954 and MDA-MB-453 was 95.7 pM and 100.9 pM, respectively. The analyses were performed three times. The error bars represent one standard deviation. d-e Inhibition of protein synthesis by trastuzumab-PE24 in (d) HCC1954 cells and (e) MDA-MB-231 cells. Cellular proteins were labeled with a methionine surrogate of azidohomoalanine (AHA) after treating with trastuzumab, PE24, or trastuzumab-PE24. The presence of azide of AHA in proteome was detected by western blot using streptavidin-HRP conjugate after the Cu(I)-catalyzed click reaction with biotin-PEG4-alkyne. GAPDH: glyceraldehyde-3-phosphate dehydrogenase