Allosteric site

Allosteric site is a term used in biochemistry and molecular biology to describe a specific location on a protein or enzyme where a molecule, known as an allosteric effector or allosteric ligand, can bind. This binding can influence the protein's activity, often by changing its shape or conformation. Allosteric sites are distinct from the protein's active site, where the protein's primary chemical activity occurs.

Overview

The concept of the allosteric site was first proposed in the 1960s by Monod, Wyman, and Changeux who suggested that proteins could exist in multiple conformations and that the binding of a molecule to an allosteric site could shift the equilibrium between these states. This model, known as the MWC model, has been influential in our understanding of protein function and regulation.

Allosteric sites can be found on a wide range of proteins, including enzymes, receptors, and ion channels. The binding of an allosteric effector to these sites can either enhance or inhibit the protein's activity. This regulation plays a crucial role in many biological processes, such as metabolism, signal transduction, and gene expression.

Allosteric Regulation

Allosteric regulation refers to the process by which the activity of a protein is modulated through the binding of an allosteric effector to an allosteric site. This can occur through two main mechanisms: positive allosteric regulation and negative allosteric regulation.

In positive allosteric regulation, the binding of the effector increases the protein's activity. This often occurs by stabilizing the protein in a conformation that is more active or more receptive to its substrates. In contrast, negative allosteric regulation involves the binding of an effector that decreases the protein's activity, often by stabilizing an inactive conformation.

Allosteric Drugs

Due to their ability to modulate protein activity, allosteric sites have become important targets for drug development. Allosteric drugs can offer several advantages over traditional drugs that target active sites, including greater specificity, less risk of resistance, and the ability to fine-tune protein activity rather than completely activating or inhibiting it.

See Also

• Allosteric regulation
• Allosteric enzyme
• Allosteric modulator
• Allosteric transition