What is the Difference Between Ergosterol and Cholesterol

The key difference between ergosterol and cholesterol is that ergosterol is the major sterol found in the plasma membrane of yeast and fungi, while cholesterol is the major sterol found in the plasma membrane of animals.

Sterols are organic compounds with the formula of C₁₇H₂₈O. Generally, any compound that contains a gonane (C₁₇H₂₈) structure, additional functional groups, and modified ring systems are called sterols. They are found naturally in most eukaryotes, including plants, animals, and fungi. Sometimes, they can also be made by bacteria. Ergosterol is the prominent sterol in yeast and fungi. The most common type of animal sterol is cholesterol, which is vital to animal cell membranes and functions. It is also a precursor to fat-soluble vitamins and steroid hormones. Ergosterol and cholesterol are two prominent sterols in eukaryotes.

CONTENTS

1. Overview and Key Difference
2. What is Ergosterol 
3. What is Cholesterol
4. Similarities – Ergosterol and Cholesterol
5. Ergosterol vs Cholesterol in Tabular Form
6. Summary – Ergosterol vs Cholesterol

What is Ergosterol?

Ergosterol is the major sterol found in the plasma membrane of yeast, fungi, and protozoa. It performs many of the same functions that are normally performed by cholesterol in animal cells. Therefore, many fungi and protozoa cannot survive without ergosterol. Ergosterol is believed to have evolved as a nearly ubiquitous, evolutionary advantageous fungal alternative to animal cholesterol.

Moreover, the enzymes that synthesize ergosterol have become an important target for drug discovery. Hence, it is a useful target for antifungal drugs such as amphotericin B, fluconazole, miconazole, itraconazole, clotrimazole, and myclobutanil. Antiprotozoal drugs also work by targeting ergosterol. Human nutritional compounds also may contain ergosterol. This is because ergosterol is a provitamin form of vitamin D. Exposure to ultraviolet light causes chemical changes that produce vitamin D2 from ergosterol. Furthermore, ergosterol powder is an irritant to the skin, eyes, and respiratory tract. Ingestion of large amounts may cause hyperglycemia, which leads to calcium salt deposits in soft tissues and kidneys.

What is Cholesterol?

Cholesterol is the major sterol found in the plasma membrane of animals. It belongs to a class of certain organic molecules called lipids. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. François Poulletier de la Salle identified cholesterol form gallstone in 1769. However, this compound was first named cholesterol by Michael Eugene Chevreul. When it is chemically isolated, it looks like a yellowish crystalline solid. Cholesterol is also a precursor for the biosynthesis of steroid hormones, bile acid, and vitamin D.

Cholesterol is the prominent sterol synthesized by all animals. In vertebrates, hepatic cells produce the greatest amounts. Cholesterol is absent in most bacteria except Mycoplasma, which needs cholesterol for its growth. Furthermore, according to the lipid hypothesis, elevated levels of cholesterol in the blood cause atherosclerosis, which may increase the risk of heart attack, stroke, and peripheral artery disease.

What are the Similarities Between Ergosterol and Cholesterol?

• Ergosterol and cholesterol are two prominent sterols in eukaryotes.
• Both are organic molecules.
• Both are lipids in nature.
• They perform very important functions and are extremely important for the survival of organisms.
• They are important targets for drug discovery for a variety of diseases.
• Excess amounts of both can cause diseases in humans.

What is the Difference Between Ergosterol and Cholesterol?

Ergosterol is the major sterol found in the plasma membrane of yeast and fungi, while cholesterol is the major sterol found in the plasma membrane of animals. Thus, this is the key difference between ergosterol and cholesterol. Furthermore, ergosterol has an additional double bond in a ring of the steroid nucleus and a double bond and an extra methyl group on the alkyl side chain. On the other hand, cholesterol does not have an additional double bond in a ring of the steroid nucleus, a double bond, or an extra methyl group on the alkyl side chain.

The below infographic presents the differences between ergosterol and cholesterol in tabular form for side-by-side comparison.

Summary – Ergosterol vs Cholesterol

Ergosterol and cholesterol are two prominent sterols in eukaryotes. They are primarily lipid molecules. They also play vital roles in the survival of organisms. Ergosterol is the major sterol found in the plasma membrane of yeast and fungi, while cholesterol is the major sterol found in the plasma membrane of animals. So, this summarizes the difference between ergosterol and cholesterol.

Reference:

1. “Ergosterol.” An Overview | ScienceDirect Topics.
2. “Cholesterol Information.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention.

Image Courtesy:

1. “Ergosterol molecule ball” By Jynto (talk) – This image was created with Discovery Studio Visualizer. (CC0) via Commons Wikimedia
2. “Cholesterol-from-xtal-3D-bs” By Ben Mills – Own work (Public Domain) via Commons Wikimedia