Purified opioid mu-receptor is of a different molecular size than delta- and kappa-receptors.
Opioid mu-receptors were solubilized from rat brains with 0.5% Triton X-100 in the presence of 0.32 M sucrose and then purified with 6-succinyl morphine-Affi-Gel 102 column. Purified materials showed a major band with mol.wt. 58,000 Da and a minor band with mol.wt. 41,000 Da. Affinity cross linking with [3H]DAGO, a selective mu-opioid agonist, to the neural membranes and purified materials revealed that opioid mu-binding protein has a mol.wt. of 58,000 Da, a value totally different from that of delta- (mol.wt. 18,500 Da) and kappa- (mol.wt. 36,000 Da) binding protein.
D000818:Animals; D001923:Brain Chemistry; D055598:Chemical Phenomena; D002621:Chemistry; D004399:Dynorphins / Q000378:metabolism; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000378:metabolism; D008024:Ligands; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000302:isolation & purification*; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu
D004745:Enkephalins; D008024:Ligands; D010446:Peptide Fragments; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004399:Dynorphins; D020881:Enkephalin, D-Penicillamine (2,5)-