Figure 4
The EC50 and binding specificities of LAP-anti-EGFR antibodies before and after MMP-2 digestion. The binding kinetic of the anti-EGFR antibody (
), LAP-anti-EGFR antibody (
) and MMP-2-activated LAP-anti-EGFR antibody (
) in (A) MDA-MB-468 and (B) HaCaT cells. Note that the curve of LAP-anti-EGFR antibody is shifted to the right in both groups. In the MDA-MB-468 cells (high EGFR expression), the EC50 values for the anti-EGFR antibody, LAP-anti-EGFR antibody and MMP-2-activated LAP-anti-EGFR antibody were 2.4 nM, 7.5 nM and 2.7 nM, respectively. In the HaCaT cells (moderate EGFR expression), the EC50 values for the anti-EGFR antibody, LAP-anti-EGFR antibody and MMP-2-activated LAP-anti-EGFR antibody were 2.4 nM, 18.1 nM and 2.1 nM, respectively. (C) The anti-EGFR antibody (
), LAP-anti-EGFR antibody (
) and MMP-2-treated LAP-anti-EGFR antibody (
) were used to compete against a HA-tagged anti-EGFR antibody for binding to EGFR expressed on the cells. Bound HA-tagged anti-EGFR antibody was detected by an anti-HA antibody.
