Sandbox Reserved 1058: Difference between revisions

From Proteopedia
Jump to navigationJump to search
No edit summary
No edit summary
Line 36: Line 36:




[[Image:Complete_Mechanism.PNG|500 px|left|thumb|'''Figure 7. Observed Mechanism for the Breakdown of Isocitrate by 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.]]
[[Image:Complete_Mechanism.PNG|500 px|left|thumb|'''Figure 7. Observed Mechanism for the Breakdown of Isocitrate by 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.