On the significance of hydrogen bonds for the discrimination between CO and O2 by myoglobin
Sigfridsson, Emma LU and Ryde, Ulf LU
(1999)
In Journal of Biological Inorganic Chemistry
4(1).
p.99-110
- Abstract
Quantum chemical geometry optimisations have been performed on realistic models of the active site of myoglobin using density functional methods. The energy of the hydrogen bond between the distal histidine residue and CO or O2 has been estimated to be 8 kJ/mol and 32 kJ/mol, respectively. This 24 k J/mol energy difference accounts for most of the discrimination between CO and O2 by myoglobin (about 17 kJ/mol). Thus, steric effects seem to be of minor importance for this discrimination. The Fe-C and C-O vibrational frequencies of CO-myoglobin have also been studied and the results indicate that CO forms hydrogen bonds to either the distal histidine residue or a water molecule during normal conditions. We have made... (More)
Quantum chemical geometry optimisations have been performed on realistic models of the active site of myoglobin using density functional methods. The energy of the hydrogen bond between the distal histidine residue and CO or O2 has been estimated to be 8 kJ/mol and 32 kJ/mol, respectively. This 24 k J/mol energy difference accounts for most of the discrimination between CO and O2 by myoglobin (about 17 kJ/mol). Thus, steric effects seem to be of minor importance for this discrimination. The Fe-C and C-O vibrational frequencies of CO-myoglobin have also been studied and the results indicate that CO forms hydrogen bonds to either the distal histidine residue or a water molecule during normal conditions. We have made several attempts to optimize structures with the deprotonated nitrogen atom of histidine directed towards CO. However, all such structures lead to unfavourable interactions between the histidine and CO, and to ν(CO) frequencies higher than those observed experimentally.
(Less)
- author
- Sigfridsson, Emma
LU
and Ryde, Ulf
LU
- organization
- publishing date
- 1999
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- CO/O discrimination, Hydrogen bond, Myoglobin, Quantum chemical calculations, Vibrational frequencies
- in
- Journal of Biological Inorganic Chemistry
- volume
- 4
- issue
- 1
- pages
- 12 pages
- publisher
- Springer
- external identifiers
-
- pmid:10499107
- scopus:0032957265
- ISSN
- 0949-8257
- DOI
- 10.1007/s007750050293
- language
- English
- LU publication?
- yes
- id
- 8dfd1b38-f027-46a0-8707-ba8dc8d7b3f0
- date added to LUP
- 2017-02-04 11:42:27
- date last changed
- 2025-01-07 06:09:00
@article{8dfd1b38-f027-46a0-8707-ba8dc8d7b3f0,
abstract = {{<p>Quantum chemical geometry optimisations have been performed on realistic models of the active site of myoglobin using density functional methods. The energy of the hydrogen bond between the distal histidine residue and CO or O<sub>2</sub> has been estimated to be 8 kJ/mol and 32 kJ/mol, respectively. This 24 k J/mol energy difference accounts for most of the discrimination between CO and O<sub>2</sub> by myoglobin (about 17 kJ/mol). Thus, steric effects seem to be of minor importance for this discrimination. The Fe-C and C-O vibrational frequencies of CO-myoglobin have also been studied and the results indicate that CO forms hydrogen bonds to either the distal histidine residue or a water molecule during normal conditions. We have made several attempts to optimize structures with the deprotonated nitrogen atom of histidine directed towards CO. However, all such structures lead to unfavourable interactions between the histidine and CO, and to ν(CO) frequencies higher than those observed experimentally.</p>}},
author = {{Sigfridsson, Emma and Ryde, Ulf}},
issn = {{0949-8257}},
keywords = {{CO/O discrimination; Hydrogen bond; Myoglobin; Quantum chemical calculations; Vibrational frequencies}},
language = {{eng}},
number = {{1}},
pages = {{99--110}},
publisher = {{Springer}},
series = {{Journal of Biological Inorganic Chemistry}},
title = {{On the significance of hydrogen bonds for the discrimination between CO and O<sub>2</sub> by myoglobin}},
url = {{https://lup.lub.lu.se/search/files/135489783/31_myo.pdf}},
doi = {{10.1007/s007750050293}},
volume = {{4}},
year = {{1999}},
}