title: Isolation and characterization of a multiplication-stimulating activity (MSA)-like polypeptide produced by a human fibrosarcoma cell line.
abstract: A human fibrosarcoma cell line, 8387, produces and secretes multiplication-stimulating activity (MSA)-like polypeptide growth factors, which are associated with a high molecular weight binding protein. The purification of 8387-MSA involved concentration of serum-free media conditioned by 8387 cells, dialysis, and chromatography of the acid-soluble growth-promoting activity on Bio-Gel P-100 in 1 M acetic acid and subsequently on carboxymethylcellulose. The purification was followed by a radioreceptor assay specific for MSA and an assay for growth-stimulating activity. Both activities chromatographed through the purification steps of 8387-MSA. 8387-MSA competes with 125I-labeled rat MSA for binding on rat cells with a specific activity 5 times lower than that of rat MSA and stimulates [3H]-thymidine incorporation into DNA of normal rat fibroblasts at comparable concentrations. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the MSA-competing activity co-migrated with a single band of protein that behaved heterogeneously on discpolyacrylamide gels in the presence of 6 M urea, yielding two bands associated with biological activity. 8387-MSA is a single chain polypeptide with an apparent molecular weight of 14,500.
mesh_terms: D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D005354:Fibrosarcoma / Q000503:physiopathology*; D006801:Humans; D007335:Insulin-Like Growth Factor II; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D007708:Kirsten murine sarcoma virus; D008099:Liver; D010455:Peptides / Q000302:isolation & purification* / Q000494:pharmacology; D051381:Rats; D011955:Receptors, Drug / Q000378:metabolism; D012513:Sarcoma, Experimental / Q000378:metabolism
chemical_list: D010455:Peptides; D011955:Receptors, Drug; D007335:Insulin-Like Growth Factor II; D004247:DNA