Comparative analysis of polysaccharide and cell wall structure in Aspergillus nidulans and Aspergillus fumigatus by solid-state NMR

• Published in: Carbohydrate polymers 2025-01, Vol.348 (Pt A), p.122907, Article 122907
• Main Authors: Gautam, Isha, Yarava, Jayasubba Reddy, Xu, Yifan, Li, Reina, Scott, Faith J., Mentink-Vigier, Frederic, Momany, Michelle, Latgé, Jean-Paul, Wang, Tuo
• Format: Article
• Language: English
• Subjects: Aspergillus; Aspergillus fumigatus - chemistry; Aspergillus nidulans - chemistry; Aspergillus nidulans - metabolism; Cell wall; Cell Wall - chemistry; Chitin; Chitin - chemistry; DNP; Fungi; Galactose - analogs & derivatives; Galactose - chemistry; Glucan; Glucans - chemistry; Magnetic Resonance Spectroscopy - methods; Mannans - chemistry; Polysaccharide; Polysaccharides - chemistry; Solid-state NMR
• ISSN: 0144-8617; 1879-1344; 1879-1344
• DOI: 10.1016/j.carbpol.2024.122907

Invasive aspergillosis poses a significant threat to immunocompromised patients, leading to high mortality rates associated with these infections. Targeting the biosynthesis of cell wall carbohydrates is a promising strategy for antifungal drug development and will be advanced by a molecular-level understanding of the native structures of polysaccharides within their cellular context. Solid-state NMR spectroscopy has recently provided detailed insights into the cell wall organization of Aspergillus fumigatus, but genetic and biochemical evidence highlights species-specific differences among Aspergillus species. In this study, we employed a combination of 13C, 15N, and 1H-detection solid-state NMR, supplemented by Dynamic Nuclear Polarization (DNP), to compare the structural organization of cell wall polymers and their assembly in the cell walls of A. fumigatus and A. nidulans, both of which are key model organisms and human pathogens. The two species exhibited a similar rigid core architecture, consisting of chitin, α-glucan, and β-glucan, which contributed to comparable cell wall properties, including polymer dynamics, water retention, and supramolecular organization. However, differences were observed in the chitin, galactosaminogalactan, protein, and lipid content, as well as in the dynamics of galactomannan and the structure of the glucan matrix. [Display omitted] •Polysaccharides of two Aspergillus species were analyzed using solid-state NMR.•A conserved rigid core of the cell wall is formed by chitin, α-glucans, and β-glucans.•A. fumigatus and A. nidulans exhibit consistent hydration and polymer dynamics.•Restructured β-1,3-glucan matrix in A. nidulans, lacking the β-1,3/1,4 terminal domain.•Highly dynamic galactomannan in A. fumigatus is only partially dynamic in A. nidulans.