|
背景
|
PDGF was originally discovered as a major mitogenic factor in serum but not in plasma. PDGF is stored in platelet alpha granules and released upon platelet activation. Besides megakaryocytes, other cell types, including endothelial cells, monocyte/macrophages, vascular smooth muscle cells, fibroblasts, cytotrophoblasts and a variety of transformed or neoplastic cells, have been shown to produce PDGF. PDGFs are disulfide-linked dimers. The subunits of the PDGF dimers are homologous polypeptides designated PDGF-A and PDGF-B chains. Natural PDGFs can exist either as homodimers (PDGF-AA, PDGF-BB) or heterodimers (PDGF-AB). Although all three isoforms of PDGF exist in human platelets, R&D Systems hPDGF consists predominantly of hPDGF-AB heterodimers.
|
