Tailoring of a membrane-active peptide with dual biological activities

• Applicant: Professorin Dr. Ines Neundorf
• Subject Area: Pharmacy ; Biological and Biomimetic Chemistry
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 410897008

• Final Report Year: 2023

Final Report Abstract

The number of people suffering from cancer or multi-resistant infections is steadily increasing, such that both disease states are already seen as current and future major causes of death. Antimicrobial peptides (AMPs) count to the class of membrane-active peptides. They are part of the innate immune system, structurally diverse and rapidly act to inactivate invading microorganisms. Owing to their alternative activity mechanisms compared to conventional antibiotics, they are seen as promising contenders in the fight against infections. Moreover, there is now an abundance of evidence that cationic antimicrobial peptides possess dual activity, both as antimicrobial and anticancer peptides. In recent years, it has been shown that they are effective at restraining cancer cell proliferation, and have consequently stimulated significant interest in their development as novel biologic agents to safeguard human health. Since several years, we work on cell-penetrating peptides (CPP), which also fall in the class of membrane-active peptides and have the ability to translocate in various cell types. We have developed the CPP sC18 and have used it in many applications as versatile drug transporter for different bioactive cargoes, such as small molecule drugs, cytotoxic metal organic complexes, or peptides. Within this project we have tuned and modified sC18 in such a way that it selectively targets bacterial cells. Since CPPs and AMPs share several physicochemical characteristics, we hypothesized that we can rationally direct the activity of a CPP towards antimicrobial activity. Therefore, we have screened a synthetic library, based on the CPP sC18, including structure-based design to identify the active residues within a CPP sequence and to discover novel AMPs with high activity. Peptides with increased hydrophobicity were tested against various bacterial strains, and hits were further optimized leading to four generations of peptides. To increase the activity further we also incorporated fluorinated amino acid building blocks. Another interest was to apply hit compounds for coating on titanium surfaces with the aim to inhibit biofilm formation. In addition, we observed that several of the identified sC18 variants retained a pronounced anticancer effect, while non-cancerous cells were unharmed. All in all, we have identified highly promising and nearly ideal sC18 sequences worth to pursuit for the future prospect as novel agents against human malignancies.

Publications

• 14th German Peptide Symposium 2019: Influence on fluorinated amino acids on antimicrobial activity of cell-penetrating peptide sC18.
  Marco Drexelius
  
• Antimicrobial and Cell-Penetrating Peptides: How to Understand Two Distinct Functions Despite Similar Physicochemical Properties. Antimicrobial Peptides, 93–109.
  Neundorf, Ines
  
• Nanoparticles Modified with Cell-Penetrating Peptides: Conjugation Mechanisms, Physicochemical Properties, and Application in Cancer Diagnosis and Therapy. International Journal of Molecular Sciences, 21(7), 2536.
  Gessner, Isabel & Neundorf, Ines
  
• 15th German Peptide Symposium 2021: Multistep optimization of a cell-penetrating peptide towards its antimicrobial activity.
  Marco Drexelius
  
• Application of Antimicrobial Peptides on Biomedical Implants: Three Ways to Pursue Peptide Coatings. International Journal of Molecular Sciences, 22(24), 13212.
  Drexelius, Marco G. & Neundorf, Ines
  
• Multistep optimization of a cell-penetrating peptide towards its antimicrobial activity. Biochemical Journal, 478(1), 63–78.
  Drexelius, Marco; Reinhardt, Andre; Grabeck, Joshua; Cronenberg, Tom; Nitsche, Frank; Huesgen, Pitter F.; Maier, Berenike & Neundorf, Ines
  
• Synthesis of Cell-Penetrating Peptide Coated Silica Nanoparticles and Their Physicochemical and Biological Characterization. Cell Penetrating Peptides, 105–117.
  Gessner, Isabel; Klimpel, Annika & Neundorf, Ines
  
• 17th Naples Workshop on Bioactive Peptides 2022: Multistep translation of a cell-penetrating peptide into an antimicrobial peptide. (Invited oral presentation.)
  Neundorf, Ines
  
• Comparing Variants of the Cell-Penetrating Peptide sC18 to Design Peptide-Drug Conjugates. Molecules, 27(19), 6656.
  Grabeck, Joshua; Lützenburg, Tamara; Frommelt, Pia & Neundorf, Ines
  
• European Peptide Symposium 2022: Creating antimicrobial titanium surfaces by immobilizing chimeric peptide variants of sC18.
  Marco Drexelius
  
• Rational design of bifunctional chimeric peptides that combine antimicrobial and titanium binding activity. Journal of Peptide Science, 29(8).
  Drexelius, Marco; Arnold, Rebekka; Meinberger, Denise; Wilhelm, Michael; Mathur, Sanjay & Neundorf, Ines