title: Morphine enhances the phosphorylation of a 58 kDa protein in mouse brain membranes.
abstract: Morphine and [D-Ala2,D-Leu5]enkephalinamide enhance the phosphorylation of a 58 kDa protein in mouse brain synaptosomal membranes. The enhancement of phosphorylation was inhibited by naloxone, an antagonist of morphine. The phosphorylated 58 kDa protein was retained on wheat-germ-agglutinin-agarose and morphinone-Affi-Gel 401 columns and biospecifically eluted out from the columns with N-acetyl-D-glucosamine and naloxone respectively. These results suggest a strong possibility that the opiate-binding protein undergoes phosphorylation by endogenous protein kinase. Since the molecular mass of a mu-type opioid receptor in mouse brain is suggested to be 58 kDa, coincident with those of rat brain and neuroblastoma x glioma hybrid cells, it is conceivable that the phosphorylated 58 kDa protein is a mu-type receptor.
authors.affiliation: National Institute of Hygienic Sciences, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nagamatsu
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: R
authors.initials: R
authors.lastname: Teshima
authors.forename: H
authors.initials: H
authors.lastname: Ikebuchi
authors.forename: T
authors.initials: T
authors.lastname: Terao
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008970:Molecular Weight; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D010766:Phosphorylation; D011957:Receptors, Opioid / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D011957:Receptors, Opioid; D009270:Naloxone; D009020:Morphine