title: High-performance liquid chromatographic determination of peptides released by tryptic degradation from opioid peptide precursors in rat brain.
abstract: A high-performance liquid chromatographic method involving postcolumn fluorescence derivatization is described for the quantification of five fragment peptides (methionine-enkephalin-Thr-Ser-Glu-Lys, methionine-enkephalin-Lys, methionine-enkephalin-Arg, leucine-enkephalin-Lys and leucine-enkephalin-Arg) released by tryptic digestion from the opioid peptide precursors (proopiomeranocortin and proenkephalins A and B) in rat brain tissues. The tissue proteins containing the precursors are hydrolyzed with trypsin to the fragment peptides. The peptides are separated on an Asahipak ODP-50 column and on-line detected fluorometrically by using hydroxylamine, cobalt(II) and borate buffer reagents. The detection limits (S/N = 3) for the peptides are 0.7-2.8 pmol per 100 microliters injected. The distribution of the precursors in the brain tissues was also discussed on the basis of the determined values of the fragment peptides.
authors.affiliation: Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: G Q
authors.initials: GQ
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Kai
authors.forename: Y
authors.initials: Y
authors.lastname: Ohkura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000032:analysis*; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis*; D011498:Protein Precursors / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D014357:Trypsin
chemical_list: D004723:Endorphins; D010446:Peptide Fragments; D011498:Protein Precursors; D014357:Trypsin