Structure-function studies on the cyclic peptide MT-II, lactam derivative of alpha-melanotropin.

Bednarek MA, Silva MV, Arison B, MacNeil T, Kalyani RN, Huang RR, Weinberg DH

Peptides1 Jan 1999Cited by 67 (Europe PMC)

PMID10447101DOI10.1016/s0196-9781(99)00048-0PepBankPUB-10447101

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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study5

No result from this study comes from a test of the peptide.

Studies that did not test the peptide alone5

In this study, Melanotan II was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Melanotan II.

01LabNot a test of Melanotan II aloneIn vitro (cells)Activity measurement
An MT-II analog with His replaced by Ala kept affinity and agonist potency at human MC3, MC4 and MC5 receptors similar to MT-II.
In plain wordsIn lab tests, an altered MT-II analog worked about as well as MT-II at three melanocortin receptors.
Peptide
Melanotan II
Outcome
No significant changeAffinity and agonist potency of [Ala6]-MT-II at MC3, MC4 and MC5 receptors
Study
n: not reported in source
Outcome group
Receptor activity and mechanism · Pharmacology
Source sentences
Summary
Replacement of His with Ala resulted in [Ala6]-MT-II with affinity and agonist potency at human MC3, MC4, and MC5 receptors similar to MT-II.
1 context sentence(design, population, supporting numbers)
Summary · context
The alanine-substituted and the retro, enantio, and retro-enantio analogs of MT-II, a potent agonist at melanocortin (MC) receptors, were prepared by solid-phase synthesis and evaluated for their ability to bind and activate human MC3, MC4, and MC5 receptors.
In this study, Melanotan II was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Melanotan II.
Report a problemFND-1044710101
02LabNot a test of Melanotan II aloneIn vitro (cells)Activity measurement
An MT-II analog with Arg replaced by Ala was 100-fold less potent than MT-II at the melanocortin receptors.
In plain wordsIn lab tests, an MT-II analog with one amino acid changed was much less potent than MT-II.
Peptide
Melanotan II
Outcome
DecreasePotency of [Ala]-Arg MT-II analog
Study
n: not reported in source
Outcome group
Receptor activity and mechanism · Pharmacology
Source sentences
Summary
Substitution of Arg with Ala gave compound 100-fold less potent than MT-II
1 context sentence(design, population, supporting numbers)
Summary · context
The alanine-substituted and the retro, enantio, and retro-enantio analogs of MT-II, a potent agonist at melanocortin (MC) receptors, were prepared by solid-phase synthesis and evaluated for their ability to bind and activate human MC3, MC4, and MC5 receptors.
In this study, Melanotan II was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Melanotan II.
Report a problemFND-1044710102
03LabNot a test of Melanotan II aloneIn vitro (cells)Activity measurement
MT-II analogs with Phe or Trp replaced by Ala were inactive at micromolar concentrations.
In plain wordsIn lab tests, MT-II analogs with Phe or Trp changed to Ala had no activity.
Peptide
Melanotan II
Outcome
DecreaseActivity of Phe- and Trp-substituted MT-II analogs
Study
n: not reported in source
Outcome group
Receptor activity and mechanism · Pharmacology
Source sentences
Summary
but replacement of Phe or Trp with Ala led to inactive compounds (at the micromolar concentrations).
1 context sentence(design, population, supporting numbers)
Summary · context
The alanine-substituted and the retro, enantio, and retro-enantio analogs of MT-II, a potent agonist at melanocortin (MC) receptors, were prepared by solid-phase synthesis and evaluated for their ability to bind and activate human MC3, MC4, and MC5 receptors.
In this study, Melanotan II was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Melanotan II.
Report a problemFND-1044710103
04LabNot a test of Melanotan II aloneIn vitro (cells)Activity measurement
The retro, enantio and retro-enantio analogs of MT-II had markedly lower potency, showing that side-chain topology matters for receptor interaction.
In plain wordsIn lab tests, reversed or mirror-image forms of MT-II were much less potent at melanocortin receptors.
Peptide
Melanotan II
Outcome
DecreasePotency of retro, enantio and retro-enantio MT-II analogs
Study
n: not reported in source
Outcome group
Receptor activity and mechanism · Pharmacology
Source sentences
Summary
The significant drop of potency of the retro, enantio, and retro-enantio analogs of MT-II, demonstrated a crucial role of side-chain topology, and to a lesser degree, of peptide backbone in interactions of MT-II with the melanocortin receptors.
1 context sentence(design, population, supporting numbers)
Summary · context
The alanine-substituted and the retro, enantio, and retro-enantio analogs of MT-II, a potent agonist at melanocortin (MC) receptors, were prepared by solid-phase synthesis and evaluated for their ability to bind and activate human MC3, MC4, and MC5 receptors.
In this study, Melanotan II was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Melanotan II.
Report a problemFND-1044710104
05LabNot a test of Melanotan II aloneIn vitro (cell-free)Mechanism
Nuclear magnetic resonance analysis of MT-II suggested that Phe and Arg residues take part in hydrogen bonds that stabilize bent backbone conformations.
In plain wordsIn lab tests, structure analysis of MT-II suggested two amino acids help hold its bent shape.
Peptide
Melanotan II
Outcome
Not applicableNMR conformation of MT-II
Study
n: not reported in source
Outcome group
Receptor activity and mechanism · Pharmacology
Source sentences
Summary
The nuclear magnetic resonance analysis of MT-II suggested involvement of Phe and Arg residues in H-bonds stabilizing the bent conformations of the peptide backbone.
In this study, Melanotan II was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Melanotan II.
Report a problemFND-1044710105

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Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
10 Oct 2026, 09:43 UTC
Study results updated
Version 1
9 Oct 2026, 03:04 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

Publication types

Journal Article

MeSH terms

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