Enzymatic catalysis of urea decomposition: elimination or hydrolysis?
Journal
  Journal of the American Chemical Society.
Citation
  J Am Chem Soc. 126(38):11832-42
Publication date
  2004 Sep 29
Authors
  Estiu G
Merz KM
Grant agencies
  National Institute of General Medical Sciences
Grants
  NIGMS GM066859
Abstract
  We present a high-level quantum chemical study of possible reaction mechanisms associated with the catalytic decomposition of urea by a bioinorganic mimetic of the dinickel active site of urease. We chose the phthalazine-dinickel complexes of Lippard and co-workers, because these mimetics have been shown to hydrolytically degrade urea. High-level quantum chemical methodologies were utilized to identify stable intermediates and transition-state structures along several possible reaction pathways. The computed results were then used to further analyze what may occur in the active site of urease. Valuable information on the latter has been extracted from experimental data, computational approaches, and unpublished molecular dynamics simulations. On the basis of these comparative studies, we propose that both the elimination and hydrolytic pathways may compete for urea decomposition in the active site of urease.