Isolation and characterization of anti morphine analgesic peptide from canine brain

The anti-morphine peptide from canine brain, which is homologous to alpha subunit of hemoglobin of canine, has been isolated and characterized. The canine brain was homogenized and extracted in 0.1 M acetic acid. The supernatant was collected, and purified by chromatography of Sephadex G-50 and ion-exchange and RP-HPLC. A polypeptide was then obtained, which is termed as AMP5. It shows prominent antimorphine analgesic activity. AMP5 has an apparent molecular mass of 10.23kD. The isoelectric point was estimated to be around pH 6.7 by IEF. The amino acid composition of AMP5 and sequence of the N-terminal 50 amino acid residues was determined.