Advanced

The coordination chemistry of the catalytic zinc ion in alcohol dehydrogenase studied by ab initio quantum chemical calculations

Ryde, Ulf LU (1994) In International Journal of Quantum Chemistry 52(5). p.1229-1243
Abstract

The coordination chemistry of the zinc ion in the active site of alcohol dehydrogenase has been studied by the ab initio Hartree–Fock method. Geometry optimizations were performed using analytical gradients and basis sets of double‐zeta quality. Correlation effects were included at the MP2 level. The active site was modeled by Zn(HS)2XL(H2O)0–2, where X denotes ammonia or imidazole and L denotes water, methanol, ethanol, or the corresponding aldehydes or anions. It is shown that with uncharged L‐ligands the four‐coordinate complexes are about 20, 17, and 40kJ/mol more stable than are the corresponding three‐, five‐, and six‐coordinate complexes, respectively. If the L‐ligand is negatively charged, only... (More)

The coordination chemistry of the zinc ion in the active site of alcohol dehydrogenase has been studied by the ab initio Hartree–Fock method. Geometry optimizations were performed using analytical gradients and basis sets of double‐zeta quality. Correlation effects were included at the MP2 level. The active site was modeled by Zn(HS)2XL(H2O)0–2, where X denotes ammonia or imidazole and L denotes water, methanol, ethanol, or the corresponding aldehydes or anions. It is shown that with uncharged L‐ligands the four‐coordinate complexes are about 20, 17, and 40kJ/mol more stable than are the corresponding three‐, five‐, and six‐coordinate complexes, respectively. If the L‐ligand is negatively charged, only the four‐coordinate complexes are stable. These results suggest that the active‐site zinc ion in alcohol dehydrogenase prefers a coordination number of four during the catalytic reaction, especially when the nonprotein ligand is negatively charged. Ligand exchange at the zinc ion is likely to proceed by an associative mechanism with intermittent formation of a five‐coordinate complex. The results lend no support to mechanistic proposals attributing an important catalytic role to a negatively charged five‐coordinate hydroxide or alkoxide ligand. © 1994 John Wiley & Sons, Inc. Copyright © 1994 John Wiley & Sons, Inc.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Quantum Chemistry
volume
52
issue
5
pages
15 pages
publisher
John Wiley & Sons
external identifiers
  • scopus:0001631057
ISSN
0020-7608
DOI
10.1002/qua.560520508
language
English
LU publication?
no
id
8f297441-6551-4b60-a05b-307c4d7a76b4
date added to LUP
2017-02-04 11:29:59
date last changed
2017-07-23 05:24:08
@article{8f297441-6551-4b60-a05b-307c4d7a76b4,
  abstract     = {<p>The coordination chemistry of the zinc ion in the active site of alcohol dehydrogenase has been studied by the ab initio Hartree–Fock method. Geometry optimizations were performed using analytical gradients and basis sets of double‐zeta quality. Correlation effects were included at the MP2 level. The active site was modeled by Zn(HS)<sub>2</sub>XL(H<sub>2</sub>O)<sub>0–2</sub>, where X denotes ammonia or imidazole and L denotes water, methanol, ethanol, or the corresponding aldehydes or anions. It is shown that with uncharged L‐ligands the four‐coordinate complexes are about 20, 17, and 40kJ/mol more stable than are the corresponding three‐, five‐, and six‐coordinate complexes, respectively. If the L‐ligand is negatively charged, only the four‐coordinate complexes are stable. These results suggest that the active‐site zinc ion in alcohol dehydrogenase prefers a coordination number of four during the catalytic reaction, especially when the nonprotein ligand is negatively charged. Ligand exchange at the zinc ion is likely to proceed by an associative mechanism with intermittent formation of a five‐coordinate complex. The results lend no support to mechanistic proposals attributing an important catalytic role to a negatively charged five‐coordinate hydroxide or alkoxide ligand. © 1994 John Wiley &amp; Sons, Inc. Copyright © 1994 John Wiley &amp; Sons, Inc.</p>},
  author       = {Ryde, Ulf},
  issn         = {0020-7608},
  language     = {eng},
  number       = {5},
  pages        = {1229--1243},
  publisher    = {John Wiley & Sons},
  series       = {International Journal of Quantum Chemistry},
  title        = {The coordination chemistry of the catalytic zinc ion in alcohol dehydrogenase studied by ab initio quantum chemical calculations},
  url          = {http://dx.doi.org/10.1002/qua.560520508},
  volume       = {52},
  year         = {1994},
}