Chemical characterization and opioid activity of an exorphin isolated from in vivo digests of casein.
The in vivo formation of an opioid peptide (exorphin) derived from beta-casein has been proved for the first time. It was isolated from duodenal chyme of minipigs after feeding with the milk protein casein. The exorphin has been identified as a beta-casein fragment by end-group determinations and qualitative amino acid analysis of the purified peptide. This peptide, named beta-casomorphin-11, displayed substantial opioid activity in an opiate receptor-binding assay.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002364:Caseins / Q000378:metabolism*; D004063:Digestion; D004386:Duodenum / Q000378:metabolism; D004723:Endorphins / Q000302:isolation & purification* / Q000502:physiology; D008297:Male; D010446:Peptide Fragments; D010455:Peptides / Q000302:isolation & purification* / Q000502:physiology; D013552:Swine; D013556:Swine, Miniature
D000596:Amino Acids; D002364:Caseins; D004723:Endorphins; D010446:Peptide Fragments; D010455:Peptides; C047988:beta-casomorphin 11; C019178:exorphins; C021968:beta-casomorphins