Advanced NMR imaging reveals that cathelicidin-2 attacks drug-resistant Aspergillus fumigatus by first disrupting key cell wall components and then breaching the rigid wall barrier to reach the membrane.
Two-phase attackCathelicidin-2 first disrupts mobile cell wall components including galactosaminogalactan, then penetrates rigid wall domains by forcing water into hydrophobic regions
What the researchers found
Using advanced solid-state NMR techniques, researchers revealed exactly how the host-defense peptide cathelicidin-2 attacks the cell wall of Aspergillus fumigatus, a drug-resistant fungus that causes life-threatening infections. The peptide disrupts galactosaminogalactan — a key component involved in the fungus's ability to cause invasive disease — and affects other polysaccharides and amino acids in the mobile cell wall domain.
With longer exposure, cathelicidin-2 also penetrates the rigid cell wall by enhancing water infiltration into normally hydrophobic regions, eventually reaching the plasma membrane. This two-phase attack — first targeting mobile wall components, then breaching rigid defenses — explains how the peptide can overcome the complex fungal cell wall barrier that makes antifungal drug development so challenging.
Why it matters
Aspergillus fumigatus is becoming increasingly resistant to azole antifungals, the standard treatment for invasive aspergillosis, which kills up to 50% of infected patients. Understanding how antimicrobial peptides penetrate fungal cell walls is critical for designing next-generation antifungal drugs. This study provides an atomic-level view of the mechanism that could guide the design of more effective peptide-based antifungals.
The numbers in context
Solid-state NMR (1H and 13C detection) · Cathelicidin-2 vs. azole-resistant A. fumigatus · Galactosaminogalactan disrupted · Two-phase cell wall penetration mechanism · Published in Angewandte Chemie
How the study worked
The researchers used tailored solid-state NMR spectroscopy (both proton and carbon-13 detection) to analyze the cell wall composition of Aspergillus fumigatus before and after exposure to cathelicidin-2. This allowed them to observe changes in specific polysaccharides and amino acids at the molecular level, distinguishing between effects on mobile and rigid cell wall domains at different exposure times.
Who was studied
Aspergillus fumigatus cell wall preparations (in vitro)
What this study cannot tell us
This is a purely structural/mechanistic study at the molecular level — no animal or clinical data. The NMR experiments are conducted under controlled laboratory conditions that may not fully replicate the complexity of in vivo fungal infection. The specific concentrations and exposure times used may differ from what would be therapeutically relevant.
How to read the evidence
Published in Angewandte Chemie, one of the top chemistry journals globally. This is a technically sophisticated mechanistic study providing novel molecular-level insights, but it remains purely in vitro with no therapeutic testing.
When this study was published
Published in 2025 in Angewandte Chemie. Cutting-edge research reflecting the latest techniques in structural biology applied to antimicrobial peptide mechanisms.
The bigger picture
Antifungal resistance is a growing crisis, with the WHO listing Aspergillus fumigatus as a critical priority pathogen. Antimicrobial peptides like cathelicidins represent a potential new class of antifungals, but developing them requires understanding how they interact with complex fungal cell walls. This study provides the first detailed atomic-level view of that interaction, bridging the gap between knowing that these peptides work and understanding how to make them work better.
Questions still open
- Can the two-phase cell wall penetration mechanism be exploited to design synthetic peptides with enhanced antifungal potency?
- Does cathelicidin-2 show similar cell wall disruption patterns against other drug-resistant fungal species?
- Would combining cathelicidin-2 with existing azole drugs produce synergistic antifungal effects?
Common questions
What is cathelicidin-2 and why is it being studied against fungi?
Why is Aspergillus fumigatus so hard to treat?
Read the original research
Solid-State NMR Reveals Reorganization of the Aspergillus fumigatus Cell Wall Due to a Host-Defence Peptide.
Angewandte Chemie (International ed. in English), 64(35), e202509012
Citation
Bishoyi, Ajit Kumar; van Neer, Jacq; Bahri, Salima; Lorenz, Sophie; de Cock, Hans; Baldus, Marc. (2025). Solid-State NMR Reveals Reorganization of the Aspergillus fumigatus Cell Wall Due to a Host-Defence Peptide.. Angewandte Chemie (International ed. in English), 64(35), e202509012. https://doi.org/10.1002/anie.202509012