Fig. 1

Her2-S-Fab purification from E. coli. a Bacterial expression constructs of Her2-S-Fab and control Her2-Fab. Each construct contains a pelB signal sequence for periplasmic expression; Co-expression the constructs of anti-Her2-VL-CL and anti-Her2-VH-CH1 leads to Her2-Fab; Co-expression the constructs of anti-Her2-VL-CL and anti-Her2-VH-CH1- anti-CD16 VHH leads to Her2-S-Fab; To facilitate protein detection and purification, a Flag tag or a his8 tag were added to the C-terminal of each construct. b The commassie blue staining results of Her-S-Fab after two step purification. M, molecular weight ladder, unit: kD; (c) gel filtration chromatography showed the size of Her2-S-Fab is approximately 65 kD