Human platelet-derived growth factor (PDGF): purification of PDGF-I and PDGF-II and separation of their reduced subunits.

Abstract

Human platelet-derived growth factor (PDGF) was purified from lysates of clinically outdated human platelets by a direct procedure that allowed the recovery of active PDGF from stained sodium dodecyl sulfate/polyacrylamide gels. This technique enabled the identification and purification to homogeneity of 2 active PDGF polypeptides, one with a MW of .apprx. 35,000 (PDGF-I) and the other with a MW of .apprx. 32,000 (PDGF-II). Reduced PDGF-I produced 2 inactive subunits, with MW of .apprx. 15,000 and 18,000. Reduced PDGF-II also produced 2 inactive subunits, with MW of .apprx. 15,000 and 16,000. PDGF-II may be derived from proteolytic cleavage of PDGF-I.