Search results
Results from the WOW.Com Content Network
Allosteric enzymes need not be oligomers as previously thought, [1] and in fact many systems have demonstrated allostery within single enzymes. [2] In biochemistry, allosteric regulation (or allosteric control) is the regulation of a protein by binding an effector molecule at a site other than the enzyme's active site.
Allosteric regulation of an enzyme. In the fields of biochemistry and pharmacology an allosteric regulator (or allosteric modulator) is a substance that binds to a site on an enzyme or receptor distinct from the active site, resulting in a conformational change that alters the protein's activity, either enhancing or inhibiting its function.
In a) the allosteric enzyme functions normally. In b), it is inhibited. This type of enzymes presents two binding sites: the substrate of the enzyme and the effectors. Effectors are small molecules which modulate the enzyme activity; they function through reversible, non-covalent binding of a regulatory metabolite in the allosteric site (which ...
Allosteric Database (ASD) [1] provides a central resource for the display, search and analysis of the structure, function and related annotation for allosteric molecules. Allostery is the most direct and efficient way for regulation of biological macromolecule function induced by the binding of a ligand at an allosteric site topographically ...
The activity of many enzymes is regulated by allosteric effectors. Some of these enzymes are multimeric and carry several binding sites for the regulators. Threonine deaminase was one of the first enzymes suggested to behave like hemoglobin [22] and shown to bind ligands cooperatively. [23] It was later shown to be a tetrameric protein. [24]
PFK1 is an allosteric enzyme and has a structure similar to that of hemoglobin in so far as it is a dimer of a dimer. [5] One half of each dimer contains the ATP binding site whereas the other half the substrate (fructose-6-phosphate or (F6P)) binding site as well as a separate allosteric binding site.
The glycogen phosphorylase monomer is a large protein, composed of 842 amino acids with a mass of 97.434 kDa in muscle cells. While the enzyme can exist as an inactive monomer or tetramer, it is biologically active as a dimer of two identical subunits.
The enzyme is an archetypal example of allosteric modulation of fine control of metabolic enzyme reactions. ATCase does not follow Michaelis–Menten kinetics . Instead, it lies between its low-activity, low-affinity "tense" and its high-activity, high-affinity "relaxed" states. [ 4 ]