Difference Between Chaperones and Chaperonins

The key difference between chaperons and chaperonins is that the chaperones perform a wide array of functions including folding and degradation of the protein, aiding in protein assembly, etc., whereas the key function of chaperonins is to assist in the folding of large protein molecules.

Molecular chaperons or chaperones are protein molecules that aid in the process of folding proteins into complex structures. Therefore, chaperonins are a type of chaperone, which includes heat shock proteins. Out of all types of chaperones, chaperonins are the most widely studied proteins due to the important role it plays during correct protein folding. Therefore, the action of chaperones and chaperonins prevent the irreversible aggregation of proteins and thereby enabling their functionality. Chaperones and chaperonins differ minutely based on the functionality of the two molecules.

CONTENTS

1. Overview and Key Difference
2. What are Chaperones
3. What are Chaperonins
4. Similarities Between Chaperones and Chaperonins
5. Side by Side Comparison – Chaperones vs Chaperonins in Tabular Form
6. Summary

What are Chaperones?

Chaperones are proteins that aid in protein assembly, folding of proteins and in the degradation process of the proteins. Hence, there are many classes of Molecular Chaperones. The chaperons that bind to the hydrophobic surfaces of the proteins facilitate the folding and prevent irreversible aggregation of proteins. Moreover, chaperones can be categorized into different classes based on the size and cellular compartment. Chaperonins are one of the most important classes of chaperones, which are heat shock proteins.

Furthermore, chaperones are necessary for the process of protein degradation. When the proteins undergo misfolding, the chaperones are involved in the process of ubiquitination leading to the destruction of the protein.

What are Chaperonins?

Chaperonin is a class of chaperones that are specifically involved in folding of large proteins. They have a specific structure. Chaperonins comprised a two ring structure which can either be homo – dimeric or hetero – dimeric. These two ring structures form two central cavities. Each subunit has a domain which can bind to the hydrophobic surface of the protein. Once the binding takes place, the chaperonins bring a conformational change in the protein. This allows the correct folding of the protein.

There are two major categories of chaperonins namely group I chaperonins and group II chaperonins. Group I chaperonins are prokaryotic and mainly include the bacterial heat shock proteins such as Hsp60 and prokaryotic GroEL. Group II chaperonins include the Archean and the eukaryotic chaperonins. Some of the group II chaperonins are T-complex-related polypeptide and GroES.

What are the Similarities Between Chaperones and Chaperonins?

• Chaperones and Chaperonins are proteins.
• They are mainly involved in protein folding.
• Both bind to the hydrophobic regions of the protein.
• They can be synthesized in vitro and can be used in a lot of research related to protein misfolding.

What is the Difference Between Chaperones and Chaperonins?

Chaperones are proteins that involve in protein folding, degradation and assembly. Thus, there are several subclasses of chaperones based on the mechanism of action. Some involve in protein folding while some involve in solubilization of aggregated proteins. On the other hand, chaperonins are a type of chaperones, which specifically involve in large protein folding. This is the key difference between chaperons and chaperonins. Moreover, there are two groups of chaperonins; group I chaperonins and group II chaperonins.

The below infographic presents the difference between chaperons and chaperonins in tabular form.

Summary – Chaperones vs Chaperonins

Chaperones are a broad class of biomolecules, which are proteins. They aid in protein folding, degradation and protein assembly. Chaperonins are a class of chaperones which specifically function in large protein folding. Therefore, the key difference between chaperons and chaperonins is based on the function of the two proteins. They also differ in structure. The chaperones vary in structure whereas the chaperonins have a two ringed specific structure.

Reference:

1.Slavotinek, A M, and L G Biesecker. “Unfolding the Role of Chaperones and Chaperonins in Human Disease.” Advances in Pediatrics., U.S. National Library of Medicine, Sept. 2001. Available here  

Image Courtesy:

1.”Membrane Proteins into complexes”By Medievalpacman – Own work, (CC BY-SA 3.0) via Commons Wikimedia  
2.”GroES-GroEL top”By No machine-readable author provided. (Public Domain) via Commons Wikimedia