Self-assembly and intracellular delivery of DNA by a truncated fragment derived from the Trojan peptide Penetratin

Author(s)

Mello, Lucas R. ^[1] ; Hamley, Ian W. ^[2] ; Castelletto, Valeria ^[2] ; Garcia, Bianca B. M. ^[1] ; Lourenco, Thiago C. ^[1] ; Vassiliades, Sandra V. ^[3] ; Alves, Wendel A. ^[3] ; Han, Sang W. ^[1] ; Silva, Emerson R. ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, Dept Biofis, BR-04023062 Sao Paulo, SP - Brazil

^[2] Univ Reading, Dept Chem, Reading RGD 6AD, Berks - England

^[3] Univ Fed ABC, Ctr Ciencias Nat & Humans, BR-09210580 Santo Andre, SP - Brazil

• Document type: Journal article
• Source: SOFT MATTER; v. 16, n. 20, p. 4746-4755, MAY 28 2020.
• Web of Science Citations: 0

Abstract

Penetratin is a short Trojan peptide that attracts great interest in biomedical research for its capacity to translocate biological membranes. Herein, we study in detail both self-assembly and intracellular delivery of DNA by the heptamer KIWFQNR, a truncated peptide derived from Penetratin. This shortened sequence possesses a unique design with bolaamphiphilic characteristics that preserves the longest noncationic amino acid portion found in Penetratin. These features convey amphipathicity to assist self-assembly and make it a suitable model for exploring the role of hydrophobic residues for peptide interaction and cell uptake. We show that the fragment forms peptiplexes (i.e., peptide-DNA complexes), and aggregates into long nanofibers with clear beta-sheet signature. The supramolecular structure of nanofibers is likely composed of DNA cores surrounded by a peptide shell to which the double helix behaves as a template and induces fibrillization. A nucleation and growth mechanism proceeding through liquid-liquid phase separation of coacervates is proposed for describing the self-assembly of peptiplexes. We also demonstrate that peptiplexes deliver double-stranded 200 bp DNA into HeLa cells, indicating its potential for preparing non-viral vectors for oligonucleotides through noncovalent strategies. Since the main structural features of native Penetratin are conserved in this simpler fragment, our findings also highlight the role of uncharged amino acids for structuration, and thus for the ability of Penetratin to cross cell membranes. (AU)

• FAPESP's process: 14/50867-3 - INCT 2014: National Institute of Science and Technology in Bioanalysis
• Grantee: Marco Aurelio Zezzi Arruda
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/24409-3 - Cell-Penetrating Peptides for Transport of Plasmid DNA and microRNA: from Nanoscopic Structure to Gene Delivery.
• Grantee: Emerson Rodrigo da Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/24018-1 - Polymer-Peptide Conjugates for hydrogel formulation and its usage in detection
• Grantee: Wendel Andrade Alves
• Support Opportunities: Regular Research Grants