Metabolism of beta-endorphin in plasma studied by liquid chromatography-electrospray ionization mass spectrometry
1998 (English)In: Regulatory Peptides, ISSN 0167-0115, E-ISSN 1873-1686, Vol. 73, no 1, 67-72 p.Article in journal (Refereed) Published
Degradation of synthetic human beta-endorphin by a human plasma proteinase was studied with high-performance liquid chromatography in combination with mass spectrometry. The peptide was metabolized at a rate of 25 pmol/min to the major fragments beta-endorphin (1-19) and (20-31), the latter reported as a potent inhibitor of morphine- and beta-endorphin-induced analgesia in mice. The proteinase responsible for this process was classified as a metal-dependent serine proteinase and was effectively inactivated by phenylmethylsulfonyl fluoride and ethylenediaminetetraacetic acid. Identification of the products formed during the enzymatic reaction was performed by liquid chromatography on-line with electrospray mass spectrometry, using a reversed-phase or a novel size-exclusion column capable of separating molecules between 0.1-7 kilodaltons. Peptide sequences were verified by tandem mass spectrometry experiments. The conversion of beta-endorphin may have physiological implications in the mechanism of pain. The obtained data suggest that several precautions should be considered during recovery and measurement of beta-endorphin in plasma by immunological techniques. The applied strategy may also be useful for studying metabolism of various peptidergic compounds with potential pharmacological significance.
Place, publisher, year, edition, pages
1998. Vol. 73, no 1, 67-72 p.
beta-endorphin, plasma, metabolism, mass spectrometry, HPLC
Pharmaceutical Sciences Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-50734DOI: 10.1016/S0167-0115(97)01065-3ISI: 000072450500006PubMedID: 9537675OAI: oai:DiVA.org:uu-50734DiVA: diva2:78643