Sandbox Reserved 987: Difference between revisions

From Proteopedia
Jump to navigationJump to search
No edit summary
Line 28: Line 28:
From Wikipedia, the free encyclopedia</ref></sup>
From Wikipedia, the free encyclopedia</ref></sup>


Cocaine esterase works in a three step mechanism shown below:<sup><ref>Liu J., Zhao X., Yang W., Zhan G. C. (2011) Reaction mechanism for cocaine esterase-catalyzed hydrolysis of (+)- and (-)-cocaine: unexpected common rate-determining step. J. Phys. Chem. B. 115(17), 5017-5025.</ref></sup>
Cocaine esterase works in a four step mechanism.<sup><ref>Liu J., Zhao X., Yang W., Zhan G. C. (2011) Reaction mechanism for cocaine esterase-catalyzed hydrolysis of (+)- and (-)-cocaine: unexpected common rate-determining step. J. Phys. Chem. B. 115(17), 5017-5025.</ref></sup>
1. The lone pair on from Ser117 attacks the ester.
2. The extra pair of electrons on the oxygen reform the double bond and ecgonine methyl ester leaves.
3. A water molecules, stabilized by His287, attacks the ester again.
4. The extra pair of electrons reform the double bond again and this time break the bond to Ser117, regenerating the catalyst.


[[Image:Cocaine_esterase_mechanism.jpg]]
[[Image:Cocaine_esterase_mechanism.jpg]]