1. Glucan and glycogen exist as a covalently linked macromolecular complex in the cell wall of Candida albicans and other Candida species.
- Author
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Lowman DW, Sameer Al-Abdul-Wahid M, Ma Z, Kruppa MD, Rustchenko E, and Williams DL
- Abstract
The fungal cell wall serves as the interface between the organism and its environment. Complex carbohydrates are a major component of the Candida albicans cell wall, i.e. , glucan, mannan and chitin. β-Glucan is a pathogen associated molecular pattern (PAMP) composed of β-(1 → 3,1 → 6)-linked glucopyranosyl repeat units. This PAMP plays a key role in fungal structural integrity and immune recognition. Glycogen is an α-(1 → 4,1 → 6)-linked glucan that is an intracellular energy storage carbohydrate. We observed that glycogen was co-extracted during the isolation of β-glucan from C. albicans SC5314. We hypothesized that glucan and glycogen may form a macromolecular species that links intracellular glycogen with cell wall β-(1 → 3,1 → 6)-glucan. To test this hypothesis, we examined glucan-glycogen extracts by multi-dimensional NMR to ascertain if glycogen and β-glucan were interconnected.
1 H NMR analyses confirmed the presence of glycogen and β-glucan in the macromolecule. Diffusion Ordered SpectroscopY (DOSY) confirmed that the β-glucan and glycogen co-diffuse, which indicates a linkage between the two polymers. We determined that the linkage is not via peptides and/or small proteins. Our data indicate that glycogen is covalently linked to β-(1 → 3,1 → 6) glucan via the β -(1 → 6)-linked side chain. We also found that the glucan-glycogen complex was present in C. dublinensis , C. haemulonii and C. auris , but was not present in C. glabrata or C. albicans hyphal glucan. These data demonstrate that glucan and glycogen form a novel macromolecular complex in the cell wall of C. albicans and other Candida species . This new and unique structure expands our understanding of the cell wall in Candida species., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Author(s).)- Published
- 2021
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