PMID- 21308811
OWN - NLM
STAT- MEDLINE
DCOM- 20110413
LR  - 20110223
IS  - 1521-3765 (Electronic)
IS  - 0947-6539 (Linking)
VI  - 17
IP  - 10
DP  - 2011 Mar 1
TI  - Stereoelectronic requirements for optimal hydrogen-bond-catalyzed enolization.
PG  - 2859-66
LID - 10.1002/chem.201002943 [doi]
AB  - Protein crystallographic analysis of the active sites of enolizing enzymes and 
      structural analysis of hydrogen-bonded carbonyl compounds in small molecule 
      crystal structures, complemented by quantum chemical calculations on related 
      model enolization reactions, suggest a new stereoelectronic model that accounts 
      for the observed out-of-plane orientation of hydrogen-bond donors (HBDs) in the 
      oxyanion holes of enolizing enzymes. The computational results reveal that the 
      lone-pair directionality of HBDs characteristic for hydrogen-bonded carbonyls is 
      reduced upon enolization, and the enolate displays almost no directional 
      preference for hydrogen bonding. Positioning the HBDs perpendicular to the 
      carbonyl plane induces strain in the catalyst-substrate complex, which is 
      released upon enolization, resulting in more favorable kinetics and 
      thermodynamics than the in-plane arrangement of HBDs.
CI  - Copyright (c) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
FAU - Papai, Imre
AU  - Papai I
AD  - Department of Theoretical Chemistry, Chemical Research Center of the Hungarian 
      Academy of Sciences, Pusztaszeri ut 59-67, H-1025 Budapest, Hungary. 
      papai@chemres.hu
FAU - Hamza, Andrea
AU  - Hamza A
FAU - Pihko, Petri M
AU  - Pihko PM
FAU - Wierenga, Rik K
AU  - Wierenga RK
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20110209
PL  - Germany
TA  - Chemistry
JT  - Chemistry (Weinheim an der Bergstrasse, Germany)
JID - 9513783
RN  - 0 (Ketones)
RN  - EC 5.3.3.- (Carbon-Carbon Double Bond Isomerases)
SB  - IM
MH  - Algorithms
MH  - Carbon-Carbon Double Bond Isomerases/chemistry/*metabolism
MH  - Catalysis
MH  - Humans
MH  - Hydrogen Bonding
MH  - Ketones/*chemistry
MH  - Mitochondria/enzymology
MH  - *Models, Molecular
MH  - Stereoisomerism
MH  - Thermodynamics
EDAT- 2011/02/11 06:00
MHDA- 2011/04/14 06:00
CRDT- 2011/02/11 06:00
PHST- 2010/10/12 00:00 [received]
PHST- 2011/02/11 06:00 [entrez]
PHST- 2011/02/11 06:00 [pubmed]
PHST- 2011/04/14 06:00 [medline]
AID - 10.1002/chem.201002943 [doi]
PST - ppublish
SO  - Chemistry. 2011 Mar 1;17(10):2859-66. doi: 10.1002/chem.201002943. Epub 2011 Feb 
      9.