Human peripheral blood monocytes secrete a unique form of PDGF.
PDGF isolated from platelets and forms of PDGF produced by cells transformed with the v-sis gene (PDGF B chain) or U-20S osteosarcoma cells which express the PDGF A chain gene are known to be processed as disulfide-linked dimers of approximately 30 kd. Western blot analysis with anti human PDGF antibody of the PDGF-like factor synthesized and secreted by human blood monocytes (MDGF) on SDS gels indicates that it lacks interchain disulfide bridges and behaves as a 16-kd monomer under nonreducing conditions. Additionally, MDGF exhibits different sensitivities to either formic acid or CNBr cleavage compared to PDGF A or B chain molecules indicating it may have a different primary structure. These data suggest that MDGF represents a unique form of PDGF which lacks interchain disulfide bridges and may represent a new member of the PDGF family of growth factors.
Pencev
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Department of Medicine, Medical University of South Carolina, Charleston 29425.
Grotendorst
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D001681:Biological Assay; D006801:Humans; D007158:Immunologic Techniques; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008715:Methionine / Q000032:analysis; D008970:Molecular Weight; D009000:Monocytes / Q000502:physiology*; D010449:Peptide Mapping; D010982:Platelet-Derived Growth Factor / Q000378:metabolism* / Q000648:ultrastructure
D046911:Macromolecular Substances; D010982:Platelet-Derived Growth Factor; D008715:Methionine