Homodimerization of Human Mu-Opoid Receptor Overexpressed in Sf9 Insect Cells

In this study, we demonstrate that human mu-opioid receptors do form SDS-resistant homodimers and examine the ability of human mu-opioid receptors to dimerize and the role of agonists in the dimerization. Increasing concentrations and longer exposure of agonists reduce the levels of dimmer with a corresponding increase in the levels of monomer. This effect is achieved with both peptide and alkaloid opioid agonists and it is antagonist reversible. These results suggest that human muopioid receptors are present as receptor oligomers and interconversion between dimeric and monomeric forms may be important for biological activity.