title: Human transforming growth factor beta.alpha 2-macroglobulin complex is a latent form of transforming growth factor beta.
abstract: 125I-Labeled human platelet-derived transforming growth factor beta (125I-TGF-beta) and human alpha 2-macroglobulin (alpha 2M) formed a complex as demonstrated by 5% native polyacrylamide gel electrophoresis. The 125I-TGF-beta.alpha 2M complex migrated at a position identical to that of the fast migrating form of alpha 2M. Most of the 125I-TGF-beta.alpha 2M complex could be dissociated by acid or urea treatment. When 125I-TGF-beta was incubated with serum, the high molecular weight form of 125I-TGF-beta could be immunoprecipitated by anti-human alpha 2M anti-sera as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. alpha 2M purified from platelet-rich plasma also showed the latent transforming growth factor activity and immunoreactivity of TGF-beta. These results suggest that TGF-beta.alpha 2M complex is a latent form of TGF-beta.
mesh_terms: D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D046911:Macromolecular Substances; D008744:Methylamines / Q000494:pharmacology; D010455:Peptides / Q000378:metabolism*; D015291:Transforming Growth Factors; D014357:Trypsin / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D008744:Methylamines; D010455:Peptides; D000511:alpha-Macroglobulins; D015291:Transforming Growth Factors; C027451:methylamine; D014357:Trypsin