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Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids
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Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids

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Novel α-MSH peptide analogues with broad spectrum antimicrobial activity

Paolo Grieco1, Alfonso Carotenuto, Luigia Auriemma

  • 1Department of Pharmacy, University of Naples Federico II, Naples, Italy.

Plos One
|April 30, 2013
PubMed

Insights

Novel synthetic melanocortins show broad-spectrum antimicrobial activity against bacteria and fungi. Modifications to the alpha-melanocyte-stimulating hormone (α-MSH) sequence enhance efficacy in standard growth media for potential clinical applications.

Area of Science:

  • Biochemistry
  • Microbiology
  • Medicinal Chemistry

Background:

  • Alpha-melanocyte-stimulating hormone (α-MSH) and its analogues exhibit antimicrobial properties.
  • Existing synthetic analogues possess limited efficacy under standard microbiological conditions, hindering clinical application.

Purpose of the Study:

  • To identify novel peptides with broad-spectrum antimicrobial activity in growth medium.
  • To investigate the impact of amino acid substitutions on the antimicrobial efficacy of α-MSH analogues.

Main Methods:

  • The Gly10 residue in the [DNal(2')-7, Phe-12]-MSH(6-13) sequence was systematically replaced with various amino acids.
  • Antimicrobial activity was assessed against bacterial and fungal strains in standard growth media.
  • Conformational analysis was performed to correlate peptide structure with activity.

Main Results:

  • Two derivatives, with Gly10 substituted by Aic and Cha, demonstrated significant antimicrobial activity.
  • These novel peptides were effective against Candida species (C. albicans, C. glabrata, C. krusei) and both Gram-positive and Gram-negative bacteria.
  • Helical structure within residues 8-13 was identified as crucial for antimicrobial potency.

Conclusions:

  • Synthetic α-MSH analogues with specific structural modifications can possess potent, broad-spectrum antimicrobial activity.
  • The findings provide a basis for developing enhanced synthetic melanocortins for treating human infections.
  • Structural insights gained can guide future drug design for improved biological activity.

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