Selective amino acid substitution reduces cytotoxicity of the antimicrobial peptide mastoparan

Luz N Irazazabal; William F Porto; Suzana M Ribeiro; Sandra Casale; Vincent Humblot; Ali Ladram; Octavio L Franco

doi:10.1016/j.bbamem.2016.07.001

Selective amino acid substitution reduces cytotoxicity of the antimicrobial peptide mastoparan

Biochim Biophys Acta. 2016 Nov;1858(11):2699-2708. doi: 10.1016/j.bbamem.2016.07.001. Epub 2016 Jul 14.

Authors

Luz N Irazazabal¹, William F Porto², Suzana M Ribeiro³, Sandra Casale⁴, Vincent Humblot⁴, Ali Ladram⁵, Octavio L Franco⁶

Affiliations

¹ Molecular Pathology Post-graduate Program, University of Brasília, Brasília, Distrito Federal, Brazil.
² Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil.
³ Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil; S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, MS, Brazil.
⁴ Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, UMR 7197, Laboratoire de Réactivité de Surface (LRS), Paris, France.
⁵ Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris-Seine (IBPS), Biogenèse des Signaux Peptidiques (BIOSIPE), Paris, France.
⁶ Molecular Pathology Post-graduate Program, University of Brasília, Brasília, Distrito Federal, Brazil; Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil; S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, MS, Brazil. Electronic address: [email protected].

PMID: 27423268
DOI: 10.1016/j.bbamem.2016.07.001

Abstract

The emergence of antibiotic-resistant clinical isolates and the decreased rate of development of new antibiotics are a constant threat to human health. In this context, the therapeutic value of mastoparan (MP), a toxin from wasp venom, has been extensively studied. However, since MP shows significant cytotoxic activities, further optimization is needed. Here we evaluated the antimicrobial and cytolytic activities of an MP analog created by Ala-substitution in positions 5 and 8, named [I⁵, R⁸] mastoparan ([I⁵, R⁸] MP). We found that [I⁵, R⁸] MP displayed a broad-spectrum antimicrobial activity against bacteria and fungi (MIC in the range 3-25μM), without being hemolytic or cytotoxic toward HEK-293 cells. In addition, [I⁵, R⁸] MP-amide was highly potent (MIC=3μM) against antibiotic-resistant bacteria. The interaction with microbial membranes was investigated revealing that [I⁵, R⁸] MP is able to form an active amphipathic α-helix conformation and to disturb membranes causing lysis and cell death. Based on our findings, we hypothesize that [I⁵, R⁸] MP follows a mechanism of action similar to that proposed for MP, where the pore-forming activity leads to cell death. Our results indicate that hydrophobic moment modified by amino acid substitution may enhance MP selectivity.

Keywords: Antimicrobial peptides; Hydrophobic moment; Mastoparan; Membrane permeabilization/depolarization; Rational design.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acinetobacter baumannii / drug effects
Acinetobacter baumannii / growth & development
Amino Acid Substitution*
Anti-Bacterial Agents / chemical synthesis
Anti-Bacterial Agents / metabolism
Anti-Bacterial Agents / pharmacology*
Candida albicans / drug effects
Candida albicans / growth & development
Enterococcus faecalis / drug effects
Enterococcus faecalis / growth & development
Erythrocytes / cytology
Erythrocytes / drug effects
Escherichia coli / drug effects
Escherichia coli / growth & development
HEK293 Cells
Hemolysis / drug effects
Humans
Hydrophobic and Hydrophilic Interactions
Intercellular Signaling Peptides and Proteins
Klebsiella pneumoniae / drug effects
Klebsiella pneumoniae / growth & development
Listeria / drug effects
Listeria / growth & development
Methicillin-Resistant Staphylococcus aureus / drug effects
Methicillin-Resistant Staphylococcus aureus / growth & development
Microbial Sensitivity Tests
Peptides / chemical synthesis
Peptides / metabolism
Peptides / pharmacology*
Protein Structure, Secondary
Pseudomonas aeruginosa / drug effects
Pseudomonas aeruginosa / growth & development
Species Specificity
Streptococcus pyogenes / drug effects
Streptococcus pyogenes / growth & development
Structure-Activity Relationship
Wasp Venoms / chemical synthesis
Wasp Venoms / metabolism
Wasp Venoms / pharmacology*

Substances

Anti-Bacterial Agents
Intercellular Signaling Peptides and Proteins
Peptides
Wasp Venoms
mastoparan