The influence of adnectin binding on the extracellular domain of epidermal growth factor receptor

Area of Science:

• Biochemistry
• Structural Biology
• Pharmacology

Background:

• High-affinity protein interactions are crucial for drug design, particularly in oncology.
• Epidermal growth factor receptor (EGFR) is a key target for anticancer therapies, including antibodies and adnectins.
• Adnectins, derived from fibronectin, inhibit EGFR by binding to its extracellular domain, blocking downstream signaling.

Purpose of the Study:

• To investigate the structural consequences of adnectin binding to the extracellular domain of EGFR (exEGFR) in solution.
• To compare solution-state structural changes with existing X-ray crystallography data of the bound complex.

Main Methods:

• Hydrogen/deuterium exchange mass spectrometry (HDX MS) was employed to probe the conformational dynamics of exEGFR.
• Solution conformations of exEGFR alone and in complex with a cognate adnectin were analyzed.

Main Results:

• HDX MS identified specific structural changes in exEGFR upon adnectin binding.
• These solution-based findings were consistent with the structure of the bound complex determined by X-ray crystallography.

Conclusions:

• Adnectin binding induces conformational alterations in exEGFR that correlate with its inhibitory mechanism.
• HDX MS is a valuable tool for characterizing protein-ligand interactions in solution, complementing crystallographic studies.