The purification of an acid- and heat-labile transforming growth factor from an avian sarcoma virus- transformed rat cell line

✍ Scribed by Kazuko Yamaoka; Reiko Hirai; Akira Tsugita; Hiromi Mitsui

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 709 KB
• Volume: 119
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041190308

✦ Synopsis

A new class of transforming growth factor (TGF), with chemical characteristics differing from previously reported TGFs, was isolated and purified from an avian sarcoma virus-transformed rat cell line, 77N1. Purification steps were simple and consisted of ion-exchange chromatography on diethylaminoethyl (DEAE)-Sephacel, ammonium sulfate precipitation, Chromatofocusing, and DEAE-Sephadex A-25 chromatography. The purified TGF is a heat-and acidlabile protein with a molecular mass of 12,000 daltons and isoelectric point of 5.2-5.4. Because of the acid lability of this TGF, purification was carried out at neutral pH. The TGF induced DNA synthesis in growth-arrested BALB 3T3 cells and promoted anchorage-independent growth of nontransformed BALB 3T3 cells in soft agar; the latter activity is specific for the peptide growth factors, called TGFs, but it did not compete with epidermal growth factor (EGF) for binding to the EGF membrane receptors. T h e TCF activity was not potentiated by EGF. The purified preparation of the TGF stimulated BALB 3T3 cells to grow progressively in soft agar at a dose of 20 nglml.