Urea treatment allows dithiothreitol to release the binding subunit of the insulin receptor from the cell membrane: implications for the structural organization of the insulin receptor.
The sequence of the human insulin receptor has only one identifiable transmembrane region which is located in the beta subunit. The structure predicts that the alpha subunit, which binds insulin, is attached to the cell only by disulfide bonds to the beta subunit. However, treatment of membranes with dithiothreitol is ineffective at releasing the alpha subunit. If the receptor structure is unfolded with urea, dithiothreitol is able to release the alpha subunit. These data provided confirmatory evidence that the alpha subunit is not a transmembrane protein.
D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D004229:Dithiothreitol / Q000494:pharmacology*; D006801:Humans; D008214:Lymphocytes; D011489:Protein Denaturation; D011972:Receptor, Insulin / Q000187:drug effects* / Q000378:metabolism; D014508:Urea / Q000494:pharmacology*
D014508:Urea; D011972:Receptor, Insulin; D004229:Dithiothreitol