Beta-endorphin: demonstration of binding sites in three human neuroblastoma cell lines specific for the COOH-terminal segment of the human hormone.
This communication reports for the first time specific binding sites in human neuroblastoma cells for human beta-endorphin (beta h-EP). Three cell lines (IMR-32, NMB and Kelly) were investigated and found to bind tritiated beta h-EP with an apparent dissociation constant of 2.2-4.2 nM. Further characterization with camel beta-EP and synthetic analogs indicated that the binding is most likely mediated by the COOH-terminal segments. beta h-EP-(6-31) had significant potency (15-75%) and beta h-EP-(1-27) was without displacing activity. The camel beta-EP has below 1% of the human beta-EP activity.
D001667:Binding, Competitive; D002460:Cell Line; D003201:Computers; D004723:Endorphins / Q000378:metabolism*; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D011957:Receptors, Opioid / Q000378:metabolism*; D001615:beta-Endorphin
D004723:Endorphins; D010446:Peptide Fragments; D011957:Receptors, Opioid; D001615:beta-Endorphin