title: Isolation of a specific mu-opiate receptor peptide, morphiceptin, from an enzymatic digest of milk proteins.
abstract: Specific radioimmunoassays have been developed for the measurement of naturally occurring morphiceptin and beta-casomorphin. These peptides and related exorphins were isolated from an enzymatic digest of caseins by chromatographic techniques including gel filtration, hydrophobic column and multiple-step high pressure liquid chromatography. Three exorphins were purified and characterized in their radioimmunological, biological, and chemical properties. They were identified as morphiceptin, beta-casomorphin, and 8-prolyl-beta-casomorphin. Since morphiceptin is a highly specific mu-agonist and can be derived from a milk protein, it is possible that morphiceptin is an exogenous opioid ligand specific for mu-receptors in the brain and gastrointestinal tract.
authors.forename: K J
authors.initials: KJ
authors.lastname: Chang
authors.forename: Y F
authors.initials: YF
authors.lastname: Su
authors.forename: D A
authors.initials: DA
authors.lastname: Brent
authors.forename: J K
authors.initials: JK
authors.lastname: Chang
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000918:Antibody Specificity; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D008894:Milk Proteins / Q000032:analysis*; D011817:Rabbits; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000378:metabolism*; D017450:Receptors, Opioid, mu
chemical_list: D000596:Amino Acids; D004723:Endorphins; D008894:Milk Proteins; D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu; C021968:beta-casomorphins; C028889:morphiceptin