Growth control in cultured 3T3 fibroblasts. V. Purification of an Mr 13,000 polypeptide responsible for growth inhibitory activity.
A growth regulatory factor, which reversibly inhibits DNA synthesis and proliferation of fibroblasts, has been isolated from medium conditioned by exposure to density-inhibited mouse 3T3 cells. This factor, termed FGR-s (13K), yielded a single polypeptide (Mr 13,000) when analyzed by SDS PAGE under both reducing and nonreducing conditions. The dose-response curve of growth inhibition by FGR-s (13K) showed that 50% inhibition of 3T3 cell proliferation was achieved at a concentration of approximately 3 ng/ml, corresponding to approximately 0.23 nM. The activity of FGR-s (13K) was depleted by passing the material over an affinity column containing the monoclonal antibody 2A4; this monoclonal antibody had been previously characterized to bind to the Mr 13,000 polypeptide. These results indicate that we have purified a growth regulatory factor that acts to inhibit the proliferation of cells in an autocrine pathway.
D000818:Animals; D000911:Antibodies, Monoclonal; D001681:Biological Assay; D002453:Cell Cycle; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured / Q000166:cytology; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D006131:Growth Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D051379:Mice; D008970:Molecular Weight
D000911:Antibodies, Monoclonal; D003470:Culture Media; D006131:Growth Inhibitors