The hydrolysis of urea and the proficiency of urease.
We present the results of a computational study of the solution phase decomposition of urea, which provides insight into probable reaction pathways for the urease-catalyzed reaction. Calculations, which were used to derive thermodynamic parameters that were further used for a kinetic analysis, have been done at the solvent-corrected MP2/6-311++G** level. Both elimination and hydrolytic pathways have been considered. Elimination is favored for the solution phase reaction, which proceeds by H-bond coordination of a water molecule to the amine nitrogen atoms. The coordination of one water molecule greatly facilitates the reaction by allowing it to proceed through a cyclic six-member transition state. Aspects of the water-urea H-bond interactions have also provided insights into critical aspects of the hydrogen bond pattern in the urease active site. On the basis of a kinetic analysis, we have estimated the proficiency of urease and have predicted that it is the most proficient enzyme identified to date.
Estiu
Guillermina
G
Department of Chemistry, The Pennsylvania State University, 152 Davey Laboratory, University Park, Pennsylvania 16802-6300, USA.
Merz
Kenneth M
KM
D002384:Catalysis; D006868:Hydrolysis; D008958:Models, Molecular; D008968:Molecular Conformation; D011487:Protein Conformation; D014508:Urea / Q000737:chemistry / Q000378:metabolism*; D014510:Urease / Q000737:chemistry / Q000378:metabolism*; D014867:Water
D014867:Water; D014508:Urea; D014510:Urease