New procedure for purification of human platelet-derived growth factor

A new simple procedure was developed for purification of human platelet-derived growth factor (PDGF). PDGF was isolated and concentrated by acid/ethanol extraction of platelet lysate. Purification of this extract was accomplished by initial ion-exchange chromatography on DEAE-Sephadex and subsequent separation of "cationic" unadsorbed fraction on CM-Sephadex and controlled-pore glass--CPG-10. The product migrated as two biologically active homogeneous fractions, PDGF I (Mr = 34 000) and PDGF II (Mr = 31 000) in analytical gel electrophoresis in the presence of SDS. PDGF had isoelectric point ranging from 9.5-10.6. Multiplication-stimulating activity of PDGF was estimated using the clone of Balb/c 3T3 cells propagated in microplates in Eagle's minimal essential medium supplemented with 2% of platelet poor plasma serum. Purified PDGF was active in stimulating 3T3 cell proliferation at 0.4 ng/ml.