Receptorphin: A conserved peptide derived from the sequence of the opioid receptor, with opioid displacement activity and potent antiproliferative actions in tumor cellsReportar como inadecuado




Receptorphin: A conserved peptide derived from the sequence of the opioid receptor, with opioid displacement activity and potent antiproliferative actions in tumor cells - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

BMC Pharmacology

, 1:9

First Online: 27 November 2001Received: 06 July 2001Accepted: 27 November 2001

Abstract

BackgroundIn addition to endogenous opioids, a number of peptide sequences, derived from endogenous hemorphins, alphaS1-casomorphin, and exogenous proteins casomorphins, exorphins have been reported, possessing opioid activity. In the present work, we report the identification of a new peptide, receptorphin Tyr-Ile-Phe-Asn-Leu, derived from the sequence of the second transmembrane loop of the opioid receptor. This sequence is unique for the opioid receptor, and conserved in all species and receptor-types.

Results and DiscussionReceptorphin competes for opioid binding, presenting a kappa-receptor interaction, while it binds equally to delta- and mu- opioid and somatostatin-binding sites, and inhibits the cell proliferation of a number of human cancer cell lines, in a dose-dependent and reversible manner, at the picomolar or the nanomolar range. Receptorphin shows a preferential action on prostate cancer cells.

ConclusionOur work identifies, for the first time a peptide, in a receptor sequence, possessing ligand-agonistic activities. A hypothesis, based on receptorphin liberation after cell death, is presented, which could tentatively explain the time-lag observed during opioid antiproliferative action.

Electronic supplementary materialThe online version of this article doi:10.1186-1471-2210-1-9 contains supplementary material, which is available to authorized users.

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Autor: Marilena Kampa - Spyros Loukas - Andreas Tsapis - Elias Castanas

Fuente: https://link.springer.com/







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