Study on the self-assembly of aromatic antimicrobial peptides based on different PAF26 peptide sequences

Abstract

Antimicrobial peptide (AMP) self-assembly is an effective way to synthesis antimicrobial biomaterials. In previous studies, we found PAF26 AMP (Ac-RKKWFW-NH2) and its derivative K2–F2 peptide (Ac-KKRKKWFWFF-NH2) could both self-assemble into hydrogels, but they had distinct microscopic structures. Therefore, in this work five PAF26 peptide derivatives with different numbers of aromatic amino acids are designed to better understand the self-assembly mechanism of aromatic AMP. The transmission electron microscopy, infrared spectroscopy, circular dichroism, and fluorescence spectroscopy characterizations are carried out to study the microscope structure, secondary conformation, and molecular interactions. It is found that the five peptide derivatives have different microscopic structures, and the number of aromatic amino acids will affect the peptide hydrogen bonding and aromatic stacking interactions, causing significant differences in the secondary conformation and microscopic structure. This work will enhance the comprehension of aromatic AMP self-assembly.

pH-Dependent Reversible Self-Assembly of β-Lactoglobulin-Derived Reducing Peptides

“…(2) Ionic complementary peptides (e.g., EAR16-II, EAR8-II, EAR8-IIa, and ELR8-IIa) which are charactered by regular distribution of charged amino acid residues. 17 The oppositely charged amino acid residues provide electrostatic attractive interactions, leading to fibrilization: (3) aromatic peptides containing F, W, and Y, such as KRW6, KRW6-F, KRW6-FF, KKRW6, and KKRW6-F. 18 Fibrilization of aromatic peptides is driven by π−π stacking between aromatic rings as well as hydrogen bonds. The pH affects peptide self-assembly by modulating hydrophobic and electrostatic interactions.…”

Antimicrobial Peptides and Their Assemblies

“…The cooperative action of hydrogen bonding, hydrophobic interaction, and electrostatic attraction drive the formation of self-assembled nanostructures of AMPs; properties such as hydrophobicity, aromaticity, geometry, charge, and isoelectric point of various amino acid residues determine AMPs' secondary structures, allowing the formation of self-assembled nanostructures by carefully engineering amino acids sequences in synthetic AMPs [17,20,22,23].…”

“…Nanotechnology has also been providing promising approaches for formulating and delivering AMPs [22,[36][37][38][39]. AMPs can be protected by nanostructures, having their low stability circumvented and their release controlled by appropriate pharmacodynamics; thereby, antimicrobial activity, retention, and biosafety could be enhanced [40,41].…”

“…Approaches combining AMPs with antimicrobial nanomaterials may also lead to synergism and a broad spectrum of activity [21,42]. Figure 3 illustrates the preparation of a broadspectrum and potent antimicrobial coating based on nanoparticles (NPs) [21,42]; NPs employed were obtained from the self-assembly of gramicidin D (Gr) in a water solution (spherical Gr NPs colored in orange) [21] and antimicrobial cationic NPs based on cationic The cooperative action of hydrogen bonding, hydrophobic interaction, and electrostatic attraction drive the formation of self-assembled nanostructures of AMPs; properties such as hydrophobicity, aromaticity, geometry, charge, and isoelectric point of various amino acid residues determine AMPs' secondary structures, allowing the formation of self-assembled nanostructures by carefully engineering amino acids sequences in synthetic AMPs [17,20,22,23].…”