Lead optimization of antifungal peptides with 3D NMR structures analysis

• Published in: Protein science Vol. 13; no. 3; pp. 703 - 713
• Main Authors: Landon, Céline, Barbault, Florent, Legrain, Michèle, Menin, Laure, Guenneugues, Marc, Schott, Valérie, Vovelle, Françoise, Dimarcq, Jean‐Luc
• Format: Journal Article
• Language: English
• Published: Bristol Cold Spring Harbor Laboratory Press 01.03.2004
• Subjects: Amino Acid Sequence; Animals; antifungal; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; antimicrobial; Antimicrobial Cationic Peptides - chemistry; Antimicrobial Cationic Peptides - genetics; Antimicrobial Cationic Peptides - pharmacology; Aspergillus fumigatus - drug effects; Candida albicans - drug effects; Cloning, Molecular; Cryptococcus neoformans - drug effects; Drug Design; Fusarium - drug effects; heliomicin; Hemolymph - chemistry; Hydrophobic and Hydrophilic Interactions; insect immunity; Insect Proteins - chemistry; Insect Proteins - isolation & purification; Larva - chemistry; Lepidoptera - chemistry; Microbial Sensitivity Tests; Models, Molecular; Molecular Sequence Data; Mutagenesis, Site-Directed - genetics; NMR structure; Nuclear Magnetic Resonance, Biomolecular; Protein Conformation; Protein Structure, Secondary; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; Recombinant Proteins - pharmacology; Scedosporium - drug effects; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Static Electricity; Structural Homology, Protein; Structure-Activity Relationship; Surface Properties
• ISSN: 0961-8368; 1469-896X
• DOI: 10.1110/ps.03404404

Antimicrobial peptides are key components of the innate immune response in most multicellular organisms. These molecules are considered as one of the most innovative class of anti‐infective agents that have been discovered over the last two decades, and therefore, as a source of inspiration for novel drug design. Insect cystein‐rich antimicrobial peptides with the CSαβ scaffold (an α‐helix linked to a β‐sheet by two disulfide bridges) represent particularly attractive templates for the development of systemic agents owing to their remarkable resistance to protease degradation. We have selected heliomicin, a broad spectrum antifungal CSαβ peptide from Lepidoptera as the starting point of a lead optimization program based on phylogenic exploration and fine tuned mutagenesis. We report here the characterization, biological activity, and 3D structure of heliomicin improved analogs, namely the peptides ARD1, ETD‐135, and ETD‐151. The ARD1 peptide was initially purified from the immune hemolymph of the caterpillars of Archeoprepona demophoon. Although it differs from heliomicin by only two residues, it was found to be more active against the human pathogens Aspergillus fumigatus and Candida albicans. The peptides ETD‐135 and ETD‐151 were engineered by site‐directed mutagenesis of ARD1 in either cationic or hydrophobic regions. ETD‐135 and ETD‐151 demonstrated an improved antifungal activity over the native peptides, heliomicin and ARD1. A comparative analysis of the 3D structure of the four molecules highlighted the direct impact of the modification of the amphipathic properties on the molecule potency. In addition, it allowed to characterize an optimal organization of cationic and hydrophobic regions to achieve best antifungal activity.