Target For Antifungal Drugs
Because ergosterol is present in cell membranes of fungi, yet absent in those of animals, it is a useful target for antifungal drugs. Ergosterol is also present in the cell membranes of some protists, such as trypanosomes. This is the basis for the use of some antifungals against West African sleeping sickness.
Amphotericin B, an antifungal drug, targets ergosterol. It binds physically to ergosterol within the membrane, and, thus, creates a polar pore in fungal membranes. This causes ions (predominantly potassium and protons) and other molecules to leak out, which will kill the cell. Amphotericin B has been replaced by safer agents in most circumstances, but is still used, despite its side effects, for life-threatening fungal or protozoan infections.
Miconazole, itraconazole, and clotrimazole work in a different way, inhibiting synthesis of ergosterol from lanosterol. Ergosterol is a smaller molecule than lanosterol; it is synthesized by combining two molecules of farnesyl pyrophosphate, a 15-carbon-long terpenoid, into lanosterol, which has 30 carbons. Then, two methyl groups are removed, making ergosterol. The "azole" class of antifungal agents inhibit the enzyme that performs these demethylation steps in the biosynthetic pathway between lanosterol and ergosterol.
Read more about this topic: Ergosterol
Famous quotes containing the words target and/or drugs:
“All of women’s aspirations—whether for education, work, or any form of self-determination—ultimately rest on their ability to decide whether and when to bear children. For this reason, reproductive freedom has always been the most popular item in each of the successive feminist agendas—and the most heavily assaulted target of each backlash.”
—Susan Faludi (20th century)
“Razors pain you;
Rivers are damp;
Acids stain you;
And drugs cause cramp.
Guns aren’t lawful;
Nooses give;
Gas smells awful;
You might as well live.”
—Dorothy Parker (1893–1967)