Fumarase 2: Difference between revisions

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Similar to most enzymes involved in biological processes, fumarase can be regulated in several different ways.  Allosteric effects commonly regulate fumarase activity via substrate and inhibitor binding with the active site.  Fumarase activity is both positively and negatively regulated by substrate concentration.  When the concentration of a substrate is five-fold of the Km value, it activates fumarase’s activity; however, substrate concentrations above 0.1 M result in inhibition of fumarase function <ref name="Beeckmans, et al."/>.  The concentration of substrate influences cooperativity of fumarase, depending on the availability of substrate to bind to domains.
Similar to most enzymes involved in biological processes, fumarase can be regulated in several different ways.  Allosteric effects commonly regulate fumarase activity via substrate and inhibitor binding with the active site.  Fumarase activity is both positively and negatively regulated by substrate concentration.  When the concentration of a substrate is five-fold of the Km value, it activates fumarase’s activity; however, substrate concentrations above 0.1 M result in inhibition of fumarase function <ref name="Beeckmans, et al."/>.  The concentration of substrate influences cooperativity of fumarase, depending on the availability of substrate to bind to domains.


The regulation of fumarase via allosteric effects involves conformational changes that occur when a substrate binds to the active site.  Studies involving amino acid residue manipulation in the B site show that the B site helps regulate the binding affinity for the active site by allosteric effects <ref name="Beeckmans, et al."/>,<ref name="Rose & Weaver"/>.  According to Weaver (2004), the active site and B site are located 12 Å apart which suggests that the conformational changes resulting from <scene name='Vas_Sandbox_1/Malate_interaction/1'>malate interactions</scene>
The regulation of fumarase via allosteric effects involves conformational changes that occur when a substrate binds to the active site.  Studies involving amino acid residue manipulation in the B site show that the B site helps regulate the binding affinity for the active site by allosteric effects <ref name="Beeckmans, et al."/>,<ref name="Rose & Weaver"/>.  According to Weaver (2004), the active site and B site are located 12 Å apart which suggests that the conformational changes resulting from <scene name='Vas_Sandbox_1/Malate_interaction/2'>malate interactions</scene> with the B site influence the active site affinity to bind with the substrate <ref name="Weaver, et al."/>.  Inhibitors also regulate the activity of an enzyme via binding to the active site.  Both citrate and succinate are known as competitive inhibitors of fumarase since they negatively influence the enzyme’s activity.  They are competitive inhibitors because they have structural similarity to the substrate; therefore, the inhibitors compete with substrates to bind with the active site.  The natural state of fumarase commonly involves <scene name='Vas_Sandbox_1/Citrate_interaction/2'>citrate interactions</scene> with the active site in which similar amino acid residues responsible for binding with a substrate result in binding with a citrate molecule.
with the B site influence the active site affinity to bind with the substrate <ref name="Weaver, et al."/>.  Inhibitors also regulate the activity of an enzyme via binding to the active site.  Both citrate and succinate are known as competitive inhibitors of fumarase since they negatively influence the enzyme’s activity.  They are competitive inhibitors because they have structural similarity to the substrate; therefore, the inhibitors compete with substrates to bind with the active site.  The natural state of fumarase commonly involves <scene name='Vas_Sandbox_1/citrate_interactions/1'>citrate interaction</scene> with the active site in which similar amino acid residues responsible for binding with a substrate result in binding with a citrate molecule.