The Receptor Site for Amphotericin B
by Isabella Lombardo
Every fungus cell has a plasma membrane and every plasma membrane has
a phospholipid bilayer structure with many proteins, lipids, and sterols
embedded in it. The sterol contributes to the membrane’s fluidity
and stability as a necessary element of the plasma membrane. In addition,
sterols prevent the fatty acid portions of the membrane (nonpolar hydrophobic
tails) from packing together, crystallizing, and drastically reducing the
membrane’s fluidity. Amphotericin B binds to the sterol content of
the plasma membrane and fits right in. The antifungal antibiotic
interacts with ergosterol, the major sterol in the plasma membranes of
all fungi. This pseudo-membrane (the Amphotericin B rooted in the
ergosterol of the fungus membrane), though has a specific function.
The Amphotericin B forms pores and channels in the fungus membrane allowing
essential intracellular materials, like glucose and potassium, to leak
out and prevents vital nutrients from getting in and starving the fungus.
Eventually, this leads to cell death.