Demonstration of two subtypes of insulin-like growth factor receptors by affinity cross-linking.
The structure of receptors for insulin-like growth factors in rat liver plasma membranes and the BRL 3A2 rat liver cell line has been examined by chemical cross-linking with disuccinimidyl suberate and sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing and nonreducing conditions. Two receptor subtypes have been identified: (i) 125I multiplication-stimulating activity cross-linked to liver membranes or intact cells appeared in a complex of Mr = 260,000 (reduced) and 220,000 (nonreduced) and (ii) 125I-insulin-like growth factor I cross-linked to BRL 3A2 cells appeared predominantly in two bands of Mr greater than 300,000 without disulfide reduction and in a Mr = 130,000 complex following reduction. The two subtypes of insulin-like growth factor receptors identified by structural analysis correspond to previously observed differences in their specificity for insulin and insulin-like growth factors.
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006133:Growth Substances / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007335:Insulin-Like Growth Factor II; D008099:Liver / Q000378:metabolism*; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface / Q000032:analysis*; D017451:Receptors, Somatomedin; D013388:Succinimides
D006133:Growth Substances; D007328:Insulin; D010455:Peptides; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D013388:Succinimides; D007335:Insulin-Like Growth Factor II; C019358:disuccinimidyl suberate