Fig. 6: Schematic illustration of cell wall polysaccharide reorganization induced by caspofungin treatment.
The illustration integrates NMR observations with the biochemical understanding of A. fumigatus cell walls. a Organization of cell wall polysaccharides in untreated 3-day-old A. fumigatus mycelial cell walls. The eight molecules shown in the figure include chitin (orange), α−1,3-glucan (green for type-a, cyan for type-b, and grey for type-c), β−1,3-glucan (blue, linear), β−1,3/1,6-glucan (blue, branched), β−1,3/1,4-glucan (magenta), chitosan (purple strands), GAG (yellow), GM (brown), cell membranes (dark grey), and proteins (purple particles). b Following caspofungin treatment, the amount of β−1,3-glucan is substantially reduced while the content of chitin, chitosan, and the two minor forms of α−1,3-glucans increased. The physical contacts among the remaining biopolymers also increased. These illustrative figures are constructed based on previous models41,104 built on biochemical and imaging studies, and with new insights from current NMR analysis regarding molecular composition and intermolecular contacts. The sizes and orientations of the polymers depicted within the cell wall are hypothetical.
