Fungal cell membrane and cell envelope

The fungal cell membrane and cell envelope are vital structures that provide physical protection and maintain the physiological homeostasis of fungal cells (Nature Reviews Microbiology, 2014). The plasma membrane is a lipid bilayer primarily composed of ergosterol, which regulates membrane fluidity and permeability, while the surrounding cell wall is a complex network of chitin, beta-glucans, and mannoproteins providing structural rigidity (Journal of Fungi, 2020). These structures are critical for fungal virulence and serve as the primary targets for major antifungal classes because components like ergosterol and beta-glucans are absent in human cells (StatPearls, 2023). Polyenes like amphotericin B disrupt the membrane by binding ergosterol, whereas azoles inhibit its synthesis, and echinocandins target the cell wall by blocking glucan production. Therapeutic targeting of these structures is essential for treating systemic and superficial mycoses, although challenges such as nephrotoxicity and emerging drug resistance persist (NIH, 2022).

Other names

Fungal cell wallFungal plasma membraneMycological cell envelopeFungal cell surface

Drugs targeting the fungal cell membrane and envelope act by disrupting structural components or inhibiting their biosynthesis. Polyenes (e.g., Amphotericin B) bind to ergosterol in the fungal membrane, creating pores that cause leakage of intracellular contents (StatPearls, 2023). Azoles and allylamines inhibit enzymes in the ergosterol biosynthetic pathway—specifically lanosterol 14-alpha-demethylase and squalene epoxidase—leading to ergosterol depletion and membrane dysfunction (NIH, 2022). Echinocandins inhibit (1,3)-beta-D-glucan synthase, preventing the synthesis of a key structural polysaccharide in the cell wall, which results in osmotic instability and cell lysis (Nature Reviews Microbiology, 2014).