Structure-activity relationships of arodyn, a novel acetylated kappa opioid receptor antagonist

M. A. Bennett, Thomas F. Murray, Jane V. Aldrich

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We previously reported that the novel dynorphin A (Dyn A, Tyr-Gly-Gly-Phe-Leu-Arg-Arg-lle-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln) analog arodyn (Ac[Phe1,2,3,Arg4,D-Ala8]Dyn A-(1-11)NH2, Bennett, M.A., Murray, T.F. & Aldrich, J.V. (2002). J. Med. Chem. vol. 45, pp. 5617-5619) is a κ opioid receptor-selective peptide [Ki(κ) = 10 nM, Ki ratio (κ/μ/δ) = 1/174/583] which exhibits antagonist activity at κ opioid receptors. In this study, a series of arodyn analogs was prepared and evaluated to explore the structure-activity relationships (SAR) of this peptide; this included an alanine scan of the entire arodyn sequence, sequential isomeric D-amino acid substitution in the N-terminal 'message' sequence, NMePhe substitution individually in positions 1-3, and modifications in position 1. The results for the Ala-substituted derivatives indicated that Arg6 and Arg7 are the most important residues for arodyn's nanomolar binding affinity for κ opioid receptors. Ala substitution of the other basic residues (Arg4, Arg9 and Lys11) resulted in lower decreases in affinity for κ opioid receptors (three- to fivefold compared with arodyn). Of particular interest, while [Ala10]arodyn exhibits similar κ opioid receptor binding as arodyn, it displays higher κ vs. μ opioid receptor selectivity [Ki ratio (κ/μ) = 1/350] than arodyn because of a twofold loss in affinity at μ opioid receptors. Surprisingly, the Tyr1 analog exhibits a sevenfold decrease in κ opioid receptor affinity, indicating that arodyn displays significantly different SAR than Dyn A; [Tyr1)arodyn also unexpectedly exhibits inverse agonist activity in the adenylyl cyclase assay using Chinese hamster ovary cells stably expressing κ opioid receptors. Substitution of NMePhe in position 1 gave [NMePhe1]arodyn which exhibits high affinity [Ki(κ) = 4.56 nM] and exceptional selectivity for κ opioid receptors [Ki- ratio (κ/μ/δ) = 1/1100/>2170]. This peptide exhibits antagonistic activity in the adenylyl cyclase assay, reversing the agonism of 10 nM Dyn A-(1-13)NH2. Thus [NMePhe1]arodyn is a highly κ opioid receptor-selective antagonist that could be a useful pharmacological tool to study κ opioid receptor-mediated activities. Copyright Blackwell Munksgaard, 2005.

Original languageEnglish
Pages (from-to)322-332
Number of pages11
JournalJournal of Peptide Research
Volume65
Issue number3
DOIs
StatePublished - Mar 2005
Externally publishedYes

Fingerprint

kappa Opioid Receptor
Narcotic Antagonists
Opioid Receptors
Structure-Activity Relationship
Substitution reactions
Adenylyl Cyclases
Peptides
arodyn
Assays
Leucine Enkephalin
Dynorphins
Amino Acid Substitution
Cricetulus
Alanine
Ovary

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Endocrinology

Cite this

Structure-activity relationships of arodyn, a novel acetylated kappa opioid receptor antagonist. / Bennett, M. A.; Murray, Thomas F.; Aldrich, Jane V.

In: Journal of Peptide Research, Vol. 65, No. 3, 03.2005, p. 322-332.

Research output: Contribution to journalArticle

@article{1c5c449309c14766a6a8d62237200f21,
title = "Structure-activity relationships of arodyn, a novel acetylated kappa opioid receptor antagonist",
abstract = "We previously reported that the novel dynorphin A (Dyn A, Tyr-Gly-Gly-Phe-Leu-Arg-Arg-lle-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln) analog arodyn (Ac[Phe1,2,3,Arg4,D-Ala8]Dyn A-(1-11)NH2, Bennett, M.A., Murray, T.F. & Aldrich, J.V. (2002). J. Med. Chem. vol. 45, pp. 5617-5619) is a κ opioid receptor-selective peptide [Ki(κ) = 10 nM, Ki ratio (κ/μ/δ) = 1/174/583] which exhibits antagonist activity at κ opioid receptors. In this study, a series of arodyn analogs was prepared and evaluated to explore the structure-activity relationships (SAR) of this peptide; this included an alanine scan of the entire arodyn sequence, sequential isomeric D-amino acid substitution in the N-terminal 'message' sequence, NMePhe substitution individually in positions 1-3, and modifications in position 1. The results for the Ala-substituted derivatives indicated that Arg6 and Arg7 are the most important residues for arodyn's nanomolar binding affinity for κ opioid receptors. Ala substitution of the other basic residues (Arg4, Arg9 and Lys11) resulted in lower decreases in affinity for κ opioid receptors (three- to fivefold compared with arodyn). Of particular interest, while [Ala10]arodyn exhibits similar κ opioid receptor binding as arodyn, it displays higher κ vs. μ opioid receptor selectivity [Ki ratio (κ/μ) = 1/350] than arodyn because of a twofold loss in affinity at μ opioid receptors. Surprisingly, the Tyr1 analog exhibits a sevenfold decrease in κ opioid receptor affinity, indicating that arodyn displays significantly different SAR than Dyn A; [Tyr1)arodyn also unexpectedly exhibits inverse agonist activity in the adenylyl cyclase assay using Chinese hamster ovary cells stably expressing κ opioid receptors. Substitution of NMePhe in position 1 gave [NMePhe1]arodyn which exhibits high affinity [Ki(κ) = 4.56 nM] and exceptional selectivity for κ opioid receptors [Ki- ratio (κ/μ/δ) = 1/1100/>2170]. This peptide exhibits antagonistic activity in the adenylyl cyclase assay, reversing the agonism of 10 nM Dyn A-(1-13)NH2. Thus [NMePhe1]arodyn is a highly κ opioid receptor-selective antagonist that could be a useful pharmacological tool to study κ opioid receptor-mediated activities. Copyright Blackwell Munksgaard, 2005.",
author = "Bennett, {M. A.} and Murray, {Thomas F.} and Aldrich, {Jane V.}",
year = "2005",
month = "3",
doi = "10.1111/j.1399-3011.2005.00216.x",
language = "English",
volume = "65",
pages = "322--332",
journal = "Chemical Biology and Drug Design",
issn = "1747-0277",
publisher = "Blackwell",
number = "3",

}

TY - JOUR

T1 - Structure-activity relationships of arodyn, a novel acetylated kappa opioid receptor antagonist

AU - Bennett, M. A.

AU - Murray, Thomas F.

AU - Aldrich, Jane V.

PY - 2005/3

Y1 - 2005/3

N2 - We previously reported that the novel dynorphin A (Dyn A, Tyr-Gly-Gly-Phe-Leu-Arg-Arg-lle-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln) analog arodyn (Ac[Phe1,2,3,Arg4,D-Ala8]Dyn A-(1-11)NH2, Bennett, M.A., Murray, T.F. & Aldrich, J.V. (2002). J. Med. Chem. vol. 45, pp. 5617-5619) is a κ opioid receptor-selective peptide [Ki(κ) = 10 nM, Ki ratio (κ/μ/δ) = 1/174/583] which exhibits antagonist activity at κ opioid receptors. In this study, a series of arodyn analogs was prepared and evaluated to explore the structure-activity relationships (SAR) of this peptide; this included an alanine scan of the entire arodyn sequence, sequential isomeric D-amino acid substitution in the N-terminal 'message' sequence, NMePhe substitution individually in positions 1-3, and modifications in position 1. The results for the Ala-substituted derivatives indicated that Arg6 and Arg7 are the most important residues for arodyn's nanomolar binding affinity for κ opioid receptors. Ala substitution of the other basic residues (Arg4, Arg9 and Lys11) resulted in lower decreases in affinity for κ opioid receptors (three- to fivefold compared with arodyn). Of particular interest, while [Ala10]arodyn exhibits similar κ opioid receptor binding as arodyn, it displays higher κ vs. μ opioid receptor selectivity [Ki ratio (κ/μ) = 1/350] than arodyn because of a twofold loss in affinity at μ opioid receptors. Surprisingly, the Tyr1 analog exhibits a sevenfold decrease in κ opioid receptor affinity, indicating that arodyn displays significantly different SAR than Dyn A; [Tyr1)arodyn also unexpectedly exhibits inverse agonist activity in the adenylyl cyclase assay using Chinese hamster ovary cells stably expressing κ opioid receptors. Substitution of NMePhe in position 1 gave [NMePhe1]arodyn which exhibits high affinity [Ki(κ) = 4.56 nM] and exceptional selectivity for κ opioid receptors [Ki- ratio (κ/μ/δ) = 1/1100/>2170]. This peptide exhibits antagonistic activity in the adenylyl cyclase assay, reversing the agonism of 10 nM Dyn A-(1-13)NH2. Thus [NMePhe1]arodyn is a highly κ opioid receptor-selective antagonist that could be a useful pharmacological tool to study κ opioid receptor-mediated activities. Copyright Blackwell Munksgaard, 2005.

AB - We previously reported that the novel dynorphin A (Dyn A, Tyr-Gly-Gly-Phe-Leu-Arg-Arg-lle-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln) analog arodyn (Ac[Phe1,2,3,Arg4,D-Ala8]Dyn A-(1-11)NH2, Bennett, M.A., Murray, T.F. & Aldrich, J.V. (2002). J. Med. Chem. vol. 45, pp. 5617-5619) is a κ opioid receptor-selective peptide [Ki(κ) = 10 nM, Ki ratio (κ/μ/δ) = 1/174/583] which exhibits antagonist activity at κ opioid receptors. In this study, a series of arodyn analogs was prepared and evaluated to explore the structure-activity relationships (SAR) of this peptide; this included an alanine scan of the entire arodyn sequence, sequential isomeric D-amino acid substitution in the N-terminal 'message' sequence, NMePhe substitution individually in positions 1-3, and modifications in position 1. The results for the Ala-substituted derivatives indicated that Arg6 and Arg7 are the most important residues for arodyn's nanomolar binding affinity for κ opioid receptors. Ala substitution of the other basic residues (Arg4, Arg9 and Lys11) resulted in lower decreases in affinity for κ opioid receptors (three- to fivefold compared with arodyn). Of particular interest, while [Ala10]arodyn exhibits similar κ opioid receptor binding as arodyn, it displays higher κ vs. μ opioid receptor selectivity [Ki ratio (κ/μ) = 1/350] than arodyn because of a twofold loss in affinity at μ opioid receptors. Surprisingly, the Tyr1 analog exhibits a sevenfold decrease in κ opioid receptor affinity, indicating that arodyn displays significantly different SAR than Dyn A; [Tyr1)arodyn also unexpectedly exhibits inverse agonist activity in the adenylyl cyclase assay using Chinese hamster ovary cells stably expressing κ opioid receptors. Substitution of NMePhe in position 1 gave [NMePhe1]arodyn which exhibits high affinity [Ki(κ) = 4.56 nM] and exceptional selectivity for κ opioid receptors [Ki- ratio (κ/μ/δ) = 1/1100/>2170]. This peptide exhibits antagonistic activity in the adenylyl cyclase assay, reversing the agonism of 10 nM Dyn A-(1-13)NH2. Thus [NMePhe1]arodyn is a highly κ opioid receptor-selective antagonist that could be a useful pharmacological tool to study κ opioid receptor-mediated activities. Copyright Blackwell Munksgaard, 2005.

UR - http://www.scopus.com/inward/record.url?scp=16444386247&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=16444386247&partnerID=8YFLogxK

U2 - 10.1111/j.1399-3011.2005.00216.x

DO - 10.1111/j.1399-3011.2005.00216.x

M3 - Article

VL - 65

SP - 322

EP - 332

JO - Chemical Biology and Drug Design

JF - Chemical Biology and Drug Design

SN - 1747-0277

IS - 3

ER -