Epidermal growth factor (EGF) is a typical growth-stimulating peptide and functions by binding to specific cell-surface receptors and inducing dimerization of the receptors. Little is known about the molecular mechanism of EGF-induced dimerization of EGF receptors. The crystal structure of human EGF has been determined at pH 8.1. There are two human EGF molecules A and B in the asymmetric unit ...