EGF induces increased ligand binding affinity and dimerization of soluble epidermal growth factor (EGF) receptor extracellular domain.

摘要: The binding of epidermal growth factor (EGF) to its cell surface receptor (EGF-R) results in a number intracellular responses including the activation tyrosine kinase. Receptor oligomerization induced by ligand has been suggested play an important role signal transduction. However, mechanisms involved and transduction are poorly understood. We have produced purified several milligrams recombinant extracellular domain EGF (EGF-Rx) using baculovirus/insect expression system. baculovirus-generated EGF-Rx is glycosylated, had peptide correctly cleaved, exhibits dissociation constant for similar that solubilized full-length receptor, about 100 nM. leads formation dimers higher states which irreversibly captured covalent cross-linking agent disuccinimidyl suberate. Interestingly, monomers dimers, stabilized cross-linker presence EGF, exhibit increased affinity toward as compared with not exposed EGF. It appears high state can be maintained agent. These indicate addition binding, possesses inherent ability undergo ligand-induced dimerization low converted