with anti-MOPR antibodies [18,27,30]. The rigor and convergence of pharmacological and biochemical data provide confidence in the unequivocal identification of MOPR [see [26] for review]. This single broad band of the mature MOPR has a Mr range between 58 to 97 kDa and the median Mr above 54 kDa, depending on cell lines, brain regions and species. Upon deglycosylation to remove N-linked glycans, MOPRs became sharp bands with Mr's close to the theoretical molecular mass (∼43 kDa) of the deduced amino acid sequences [see [26] for review].
