High metabolic in vivo stability and bioavailability of a palmitoylated ghrelin receptor ligand assessed by mass spectrometry.

Autor: Kostelnik KB; Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Universität Leipzig, Brüderstraße 34, 04103 Leipzig, Germany., Els-Heindl S; Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Universität Leipzig, Brüderstraße 34, 04103 Leipzig, Germany., Klöting N; IFB AdiposityDiseases, Junior Research Group Animal Models, Universität Leipzig, Liebigstraße 21, 04103 Leipzig, Germany., Baumann S; Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Universität Leipzig, Brüderstraße 34, 04103 Leipzig, Germany; Department of Metabolomics, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany., von Bergen M; Department of Metabolomics, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany; Department of Proteomics, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany; Department of Biotechnology, Chemistry and Environmental Engineering, University of Aalborg, Denmark., Beck-Sickinger AG; Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, Universität Leipzig, Brüderstraße 34, 04103 Leipzig, Germany. Electronic address: beck-sickinger@uni-leipzig.de.
Jazyk: angličtina
Zdroj: Bioorganic & medicinal chemistry [Bioorg Med Chem] 2015 Jul 15; Vol. 23 (14), pp. 3925-32. Date of Electronic Publication: 2014 Dec 10.
DOI: 10.1016/j.bmc.2014.12.008
Abstrakt: The constitutive activity of the ghrelin receptor is of high physiological and pathophysiological relevance. In-depth structure-activity relationship studies revealed a palmitoylated ghrelin receptor ligand that displays an in vitro binding affinity in the low nanomolar range. Activity studies revealed inverse agonistic as well as antagonistic properties and in vitro metabolic analysis indicated a high stability in blood serum and liver homogenate. For metabolic testing in vivo, a combined approach of stable isotopic labeling and mass spectrometry-based analysis was established. Therefore, a heavy isotopic version of the peptide containing a (13)C-labeled palmitic acid was synthesized and a 1:1 ratio of a (12)C/(13)C-peptide mixture was injected into rats. Biological samples were analyzed by multiple reaction monitoring allowing simultaneous peptide detection and quantification. Measurements revealed a suitable bioavailability over 24h in rat serum and subsequent high-resolution mass spectrometry investigations showed only negligible degradation and slow body clearance. Hence, this method combination allowed the identification and evaluation of a highly potent and metabolically stable ghrelin receptor ligand in vivo.
(Copyright © 2014 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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