Quantitative analysis of ligand-EGFR interactions: a platform for screening targeting molecules.
Epidermal growth factor receptor (EGFR) is often constitutively stimulated in many cancers owing to the binding of ligands such as epidermal growth factor (EGF). Therefore, it is necessary to investigate the interaction between EGFR and its targeting biomolecules. The main aim of this study was to estimate the binding affinity and adhesion force of two targeting molecules, anti-EGFR monoclonal antibody (mAb LA1) and the peptide GE11 (YHWYGYTPQNVI), with respect to EGFR and to compare these values with those obtained for the ligand, EGF. Surface plasmon resonance (SPR) was used to determine the equilibrium dissociation constant (KD) for evaluating the binding affinity. Atomic force microscopy (AFM) was performed to estimate the adhesion force. In the case of EGFR, the KD of EGF, GE11, and mAb LA1 were 1.77 × 10-7, 4.59 × 10-4 and 2.07 × 10-9, respectively, indicating that the binding affinity of mAb LA1 to EGFR was higher than that of EGF, while the binding affinity of GE11 to EGFR was the lowest among the three molecules. The adhesion force between EGFR and mAb LA1 was 210.99 pN, which is higher than that observed for EGF (209.41 pN), while the adhesion force between GE11 and EGFR was the lowest (59.51 pN). These results suggest that mAb LA1 binds to EGFR with higher binding affinity than EGF and GE11. Moreover, the adhesion force between mAb LA1 and EGFR was greater than that observed for EGF and GE11. The SPR and AFM experiments confirmed the interaction between the receptor and targeting molecules. The results of this study might aid the screening of ligands for receptor targeting and drug delivery.
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Wei-Ting
WT
Kuo
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Wen-Chun
WC
Lin
Graduate Institute of Clinical Dentistry, National Taiwan University, Taipei, Taiwan.
Kai-Chun
KC
Chang
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Jian-Yuan
JY
Huang
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Ko-Chung
KC
Yen
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
In-Chi
IC
Young
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Yu-Jun
YJ
Sun
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, Taiwan.
Feng-Huei
FH
Lin
D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D018625:Microscopy, Atomic Force; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D020349:Surface Plasmon Resonance
D000911:Antibodies, Monoclonal; C572557:GE11 peptide; D010455:Peptides; D004815:Epidermal Growth Factor; D066246:ErbB Receptors