Human platelet-derived growth factor. Purification and resolution into two active protein fractions.
Human platelets secrete a factor that stimulates cultured human cells to initiate DNA synthesis and to divide. This human platelet-derived growth factor (PDGF) has been purified congruent to 100,000-fold into two equally active homogeneous fractions, PDGF I (Mr congruent to 31,000) and PDGF II (Mr congruent to 28,000). The amino acid compositions of each are similar, highly basic, and show 18 half-cystine residues. Both PDGF I and II are glycoproteins, but differ in their carbohydrate compositions. The data suggest that PDGF II may be a proteolytic cleavage product of PDGF I but do not rule out that the proteins may be separate but very similar gene products. Purified PDGF is active in stimulating DNA synthesis at 0.2 ng/ml.
D000596:Amino Acids / Q000032:analysis; D001792:Blood Platelets / Q000032:analysis*; D002241:Carbohydrates / Q000032:analysis; D006133:Growth Substances / Q000302:isolation & purification*; D006801:Humans; D008970:Molecular Weight; D010455:Peptides / Q000302:isolation & purification*; D010982:Platelet-Derived Growth Factor
D000596:Amino Acids; D002241:Carbohydrates; D006133:Growth Substances; D010455:Peptides; D010982:Platelet-Derived Growth Factor