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.
Phosphofructokinase-1 (PFK-1) is one of the most important regulatory enzymes (EC 2.7.1.11) of glycolysis. It is an allosteric enzyme made of 4 subunits and controlled by many activators and inhibitors. PFK-1 catalyzes the important "committed" step of glycolysis, the conversion of fructose 6-phosphate and ATP to fructose 1,6-bisphosphate and ...
This enzyme's main function is to synthesize or degrade allosteric regulator Fru-2,6-P 2 in response to glycolytic needs of the cell or organism, as depicted in the accompanying diagram. PFK-2 and FBPase-2 Reaction. In enzymology, a 6-phosphofructo-2-kinase (EC 2.7.1.105) is an enzyme that catalyzes the chemical reaction:
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 ...
The potential to regulate protein function is enormous given that there are many ways to covalently modify a protein in addition to regulation provided by allosteric control. In his Hopkins Memorial Lecture, Edwin Krebs asserted that allosteric control evolved to respond to signals arising from inside the cell, whereas phosphorylation evolved ...
The S 0.5 and h result in an inflection of the curve enzyme activity as a function of glucose concentration at about 4 mM. [15] In other words, at a glucose concentration of about 72 mg/dL, which is near the low end of the normal range, glucokinase activity is most sensitive to small changes in glucose concentration.
Glucose-6-phosphate dehydrogenase is the rate-controlling enzyme of this pathway [citation needed]. It is allosterically stimulated by NADP + and strongly inhibited by NADPH. [7] The ratio of NADPH:NADP + is the primary mode of regulation for the enzyme and is normally about 100:1 in liver cytosol [citation needed]. This makes the cytosol a ...