Epidermal growth factor

Human EGF is a 6-kDa protein with 53 amino acid residues and three intramolecular disulfide bonds. EGF binds to the epidermal growth factor receptor.1ivo: Crystal Structure of the Complex of Human Epidermal Growth Factor and Receptor Extracellular Domains.1jl9: Crystal Structure of Human Epidermal Growth Factor1nql: Structure of the extracellular domain of human epidermal growth factor (EGF) receptor in an inactive (low pH) complex with EGF.1p9j: Solution structure and dynamics of the EGF/TGF-alpha chimera T1E Human EGF is a 6-kDa protein with 53 amino acid residues and three intramolecular disulfide bonds. EGF binds to the epidermal growth factor receptor. EGF was originally described as a secreted peptide found in the submaxillary glands of mice and in human urine. EGF has since been found in many human tissues including submandibular gland (submaxillary gland) and parotid gland. Initially, human EGF was known as urogastrone. EGF results in cellular proliferation, differentiation, and survival. Salivary EGF, which seems to be regulated by dietary inorganic iodine, also plays an important physiological role in the maintenance of oro-esophageal and gastric tissue integrity. The biological effects of salivary EGF include healing of oral and gastroesophageal ulcers, inhibition of gastric acid secretion, stimulation of DNA synthesis as well as mucosal protection from intraluminal injurious factors such as gastric acid, bile acids, pepsin, and trypsin and to physical, chemical and bacterial agents. Epidermal growth factor can be found in urine, saliva, milk, tears and plasma.The production of epidermal growth factor has been found to be stimulated by testosterone. EGF acts by binding with high affinity to epidermal growth factor receptor (EGFR) on the cell surface. This stimulates ligand-induced dimerization, activating the intrinsic protein-tyrosine kinase activity of the receptor (see the second diagram). The tyrosine kinase activity, in turn, initiates a signal transduction cascade that results in a variety of biochemical changes within the cell – a rise in intracellular calcium levels, increased glycolysis and protein synthesis, and increases in the expression of certain genes including the gene for EGFR – that ultimately lead to DNA synthesis and cell proliferation. EGF is the founding member of the EGF-family of proteins. Members of this protein family have highly similar structural and functional characteristics. Besides EGF itself other family members include: All family members contain one or more repeats of the conserved amino acid sequence: CX7CX4-5CX10-13CXCX8GXRC