Sandbox Reserved 1058: Difference between revisions

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===Regulation===

Isocitrate lyase competes with [http://en.wikipedia.org/wiki/Isocitrate_dehydrogenase isocitrate dehydrogenase], an enzyme found in the [http://en.wikipedia.org/wiki/Citric_acid_cycle citric cycle], for isocitrate processing. The favoritism of one enzyme over the other is controlled by the phosphorylation of isocitrate dehydrogenase. This enzyme has a much higher affinity for isocitrate as compared to isocitrate lyase. Phosphorylation of isocitrate dehydrogenase inactivates the enzyme and leades to increased isocitrate lyase activity. <ref name="cozzone"> Cozzone, A.; Regulation of acetate metabolism by protein phosphorylation in enteric bacteria. ''Annual Review of Microbiology''. '''1998''', ''52'':127-164. doi: 10.1146/annurev.micro.52.1.127. </ref>

<scene name='69/694225/Isocitrate_lyase/1'>Isocitrate lyase</scene> competes with [http://en.wikipedia.org/wiki/Isocitrate_dehydrogenase isocitrate dehydrogenase], an enzyme found in the [http://en.wikipedia.org/wiki/Citric_acid_cycle citric cycle], for isocitrate processing. The favoritism of one enzyme over the other is controlled by the phosphorylation of isocitrate dehydrogenase. This enzyme has a much higher affinity for isocitrate as compared to isocitrate lyase. Phosphorylation of isocitrate dehydrogenase inactivates the enzyme and leades to increased isocitrate lyase activity. <ref name="cozzone"> Cozzone, A.; Regulation of acetate metabolism by protein phosphorylation in enteric bacteria. ''Annual Review of Microbiology''. '''1998''', ''52'':127-164. doi: 10.1146/annurev.micro.52.1.127. </ref>

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==Mechanism of Action==

[[Image:Complete_Mechanism.PNG|500 px|right|thumb|'''Figure 5. Observed Mechanism for the Breakdown of Isocitrate by Isocitrate Lyase.''']]

Within ~~isocitrate~~ lyase, His193 shifts the pKa of Cys191 and removes its proton. This allows Cys191 to extract a proton from the hydroxyl group of isocitrate. The resulting oxyanion forms a carbonyl and forces the lysis of a C-C bond. Glyoxylate and the enol form of succinate are formed and stabilized with a Mg<sup>2+</sup> ion. The succinate enolate resonates and extracts the proton back from Cys191 to form succinate ('''Figure 5''').

Within <scene name='69/694225/Isocitrate_lyase/3'>Isocitrate lyase</scene>, His193 shifts the pKa of Cys191 and removes its proton. This allows Cys191 to extract a proton from the hydroxyl group of isocitrate. The resulting oxyanion forms a carbonyl and forces the lysis of a C-C bond. Glyoxylate and the enol form of succinate are formed and stabilized with a Mg<sup>2+</sup> ion. The succinate enolate resonates and extracts the proton back from Cys191 to form succinate ('''Figure 5''').

Sandbox Reserved 1058: Difference between revisions

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@@ Line 27: / Line 27: @@
 ===Regulation===
-Isocitrate lyase competes with [http://en.wikipedia.org/wiki/Isocitrate_dehydrogenase isocitrate dehydrogenase], an enzyme found in the [http://en.wikipedia.org/wiki/Citric_acid_cycle citric cycle], for isocitrate processing. The favoritism of one enzyme over the other is controlled by the phosphorylation of isocitrate dehydrogenase. This enzyme has a much higher affinity for isocitrate as compared to isocitrate lyase. Phosphorylation of isocitrate dehydrogenase inactivates the enzyme and leades to increased isocitrate lyase activity. <ref name="cozzone"> Cozzone, A.; Regulation of acetate metabolism by protein phosphorylation in enteric bacteria. ''Annual Review of Microbiology''. '''1998''', ''52'':127-164. doi: 10.1146/annurev.micro.52.1.127. </ref>
+<scene name='69/694225/Isocitrate_lyase/1'>Isocitrate lyase</scene> competes with [http://en.wikipedia.org/wiki/Isocitrate_dehydrogenase isocitrate dehydrogenase], an enzyme found in the [http://en.wikipedia.org/wiki/Citric_acid_cycle citric cycle], for isocitrate processing. The favoritism of one enzyme over the other is controlled by the phosphorylation of isocitrate dehydrogenase. This enzyme has a much higher affinity for isocitrate as compared to isocitrate lyase. Phosphorylation of isocitrate dehydrogenase inactivates the enzyme and leades to increased isocitrate lyase activity. <ref name="cozzone"> Cozzone, A.; Regulation of acetate metabolism by protein phosphorylation in enteric bacteria. ''Annual Review of Microbiology''. '''1998''', ''52'':127-164. doi: 10.1146/annurev.micro.52.1.127. </ref>
@@ Line 34: / Line 34: @@
 ==Mechanism of Action==
 [[Image:Complete_Mechanism.PNG|500 px|right|thumb|'''Figure 5. Observed Mechanism for the Breakdown of Isocitrate by Isocitrate Lyase.''']]
-Within isocitrate lyase, His193 shifts the pKa of Cys191 and removes its proton. This allows Cys191 to extract a proton from the hydroxyl group of isocitrate. The resulting oxyanion forms a carbonyl and forces the lysis of a C-C bond. Glyoxylate and the enol form of succinate are formed and stabilized with a Mg<sup>2+</sup> ion. The succinate enolate resonates and extracts the proton back from Cys191 to form succinate ('''Figure 5''').
+Within <scene name='69/694225/Isocitrate_lyase/3'>Isocitrate lyase</scene>, His193 shifts the pKa of Cys191 and removes its proton. This allows Cys191 to extract a proton from the hydroxyl group of isocitrate. The resulting oxyanion forms a carbonyl and forces the lysis of a C-C bond. Glyoxylate and the enol form of succinate are formed and stabilized with a Mg<sup>2+</sup> ion. The succinate enolate resonates and extracts the proton back from Cys191 to form succinate ('''Figure 5''').