Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a 22kDa O-glycosylated protein that is a potent mitogen and chemoattractant for vascular smooth muscle cells, fibroblasts and epithelial cells but not endothelial cells. The natural protein has an apparent molecular mass of 19-23 kDa and exists in multiple forms as a result of heterogeneous O-glycosylation and/or Nterminal truncation. HB-EGF is synthesized as a membrane-anchored precursor(proHB-EGF) that is proteolytically cleaved to release the soluble mature growth factor. The two forms are active as juxtacrine and paracrine/autocrine growth factors respectively.HB-EGF activates two EGF receptor subtypes, HER1/ErbB1 and HER4 and binds to heparan sulfate proteoglycan.
