ALLOSTERIC REGULATION Meaning and
Definition
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Allosteric regulation is a process in which the activity of a protein or enzyme is controlled by the binding of a regulatory molecule to a site other than the active site. This binding induces a conformational change in the protein or enzyme, which in turn affects its activity.
In the case of enzymes, the binding of an allosteric regulator can either enhance (positive allosteric regulation) or inhibit (negative allosteric regulation) the enzyme's catalytic activity. This regulation allows the cell to fine-tune and control enzymatic activity in response to changes in its environment.
The allosteric site, where the regulatory molecule binds, is distinct from the active site where the substrate molecule binds and undergoes a catalytic reaction. The binding of the regulatory molecule at the allosteric site can alter the enzyme's shape, leading to changes in the enzyme's affinity for substrates.
Allosteric regulation is an important mechanism in cellular metabolism and signal transduction pathways. It plays a crucial role in maintaining homeostasis and controlling cellular processes such as metabolism, gene expression, and cell cycle regulation. By regulating enzyme activity, allosteric regulation ensures that metabolic pathways respond appropriately to changes in cellular conditions, such as substrate availability or energy levels.
Understanding the principles of allosteric regulation is vital in biomedical and pharmaceutical research. Targeting allosteric sites has the potential to develop novel drugs that modulate enzyme activity by selectively regulating their function.
Etymology of ALLOSTERIC REGULATION
The word "allosteric" has its roots in Greek. "Allo-" comes from the Greek word "allos", meaning "other", while "steric" comes from the Greek word "stereos", meaning "solid" or "solid-like".
The term "allosteric" was coined in the 1960s by two British biochemists, Monod, Wyman, and Changeux, who were studying the regulation of enzyme activity. They observed that some enzymes could be regulated by the binding of a molecule at a site other than the active site, resulting in a conformational change that affected the enzyme's activity.
They described this process as "allosteric" to signify the molecules or ligands that bind to an "other" or secondary site on the enzyme, rather than the active site where the substrate normally binds.
