Binding of 125I-insulin-like growth factor-II to cells cultured in fetal bovine serum: a complication.
Insulin-like growth factor II is an important fetal mitogen in mice and humans and its biological activity is regulated in a complex manner. The peptide interacts with three membrane-bound receptors, with a superfamily of insulin-like growth factor binding proteins and with the proteoglycan, glypican-3. Recently, the blood protein, vitronectin, has been identified as a novel insulin-like growth factor II-binding protein. Many studies have used cell lines maintained in fetal bovine serum to identify cell surface insulin-like growth factor II binding sites. We now describe a complication associated with the interpretation of such in vitro studies. Fetal bovine serum-derived vitronectin adheres very tightly to tissue culture dishes. When cells that have been maintained in fetal bovine serum are incubated with 125I-insulin-like growth factor II, a substantial fraction of the 125I-insulin-like growth factor II apparently associated with the cell surfaces may represent radioliogand bound by the fetal bovine serum-derived vitronectin. This may result in over-estimation of cell surface insulin-like growth factor II binding sites.
Galvin
C D
CD
Zoology Department, University College Dublin, Ireland.
Hardiman
O
O
Nolan
C M
CM
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003470:Culture Media; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D007457:Iodine Radioisotopes; D051379:Mice; D010969:Plastics; D011485:Protein Binding; D011869:Radioligand Assay; D019096:Vitronectin / Q000378:metabolism
D003470:Culture Media; D007457:Iodine Radioisotopes; D010969:Plastics; D019096:Vitronectin; D007335:Insulin-Like Growth Factor II