| Abstract: | A β-endorphin-(1–27)-like peptide was isolated from bovine cerebral hemisphere extracts by gel filtration, ion-exchange chromatography, high performance liquid chromatography and paper electrophoresis. The peptide had tyrosine as the amino-terminal residue and its amino acid composition was nearly identical to that of equine pituitary β-EP-(1–27). It had also the same mobility as equine pituitary β-EP-(1–27) in paper electrophoresis. In radioimmunoassay and opiate receptor-binding assay, the brain peptide had 50% activity when compared with human β-endorphin-(1–27). Evidence for the occurrence of NH2-acetylated form of β-endorphin-(1–27) is also presented. |
