Enzymatic reactions involving novel mechanisms of carbanion stabilization Academic Article uri icon

abstract

  • The reactions catalyzed by orotidine monophosphate decarboxylase, oxalate decarboxylase, organomercurial lyase and phosphopantothenoylcysteine decarboxylase involve putative high-energy carbanion intermediates that cannot be stabilized by delocalization. Mechanistic and structural studies on each of these enzymes are described that suggest different strategies for carbanion stabilization. Both orotidine monophosphate decarboxylase and organomercurial lyase are likely to avoid carbanion formation by protonating the fragmenting bond, oxalate decarboxylase stabilizes an acyl carbanion using an adjacent radical and phosphopantothenoylcysteine decarboxylase stabilizes its carbanion by delocalization into a transient thioaldehyde.

author list (cited authors)

  • Begley, T. P., & Ealick, S. E.

citation count

  • 37

publication date

  • October 2004