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Theoretical Study of Phosphodiester Hydrolysis and Transesterification Catalyzed by an Unsymmetric Biomimetic Dizinc Complex.

Daver, Henrik; Das, Biswanath LU ; Nordlander, Ebbe LU and Himo, Fahmi (2016) In Inorganic Chemistry
Abstract
Density functional theory calculations have been used to investigate the reaction mechanisms of phosphodiester hydrolysis and transesterification catalyzed by a dinuclear zinc complex of the 2-(N-isopropyl-N-((2-pyridyl)methyl)aminomethyl)-6-(N-(carboxylmethyl)-N-((2-pyridyl)methyl)amino-methyl)-4-methylphenol (IPCPMP) ligand, mimicking the active site of zinc phosphotriesterase. The substrates bis(2,4)-dinitrophenyl phosphate (BDNPP) and 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) were employed as analogues of DNA and RNA, respectively. A number of different mechanistic proposals were considered, with the active catalyst harboring either one or two hydroxide ions. It is concluded that for both reactions the catalyst has only one... (More)
Density functional theory calculations have been used to investigate the reaction mechanisms of phosphodiester hydrolysis and transesterification catalyzed by a dinuclear zinc complex of the 2-(N-isopropyl-N-((2-pyridyl)methyl)aminomethyl)-6-(N-(carboxylmethyl)-N-((2-pyridyl)methyl)amino-methyl)-4-methylphenol (IPCPMP) ligand, mimicking the active site of zinc phosphotriesterase. The substrates bis(2,4)-dinitrophenyl phosphate (BDNPP) and 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) were employed as analogues of DNA and RNA, respectively. A number of different mechanistic proposals were considered, with the active catalyst harboring either one or two hydroxide ions. It is concluded that for both reactions the catalyst has only one hydroxide bound, as this option yields lower overall energy barriers. For BDNPP hydrolysis, it is suggested that the hydroxide acts as the nucleophile in the reaction, attacking the phosphorus center of the substrate. For HPNP transesterification, on the other hand, the hydroxide is proposed to act as a Brønsted base, deprotonating the alcohol moiety of the substrate, which in turn performs the nucleophilic attack. The calculated overall barriers are in good agreement with measured rates. Both reactions are found to proceed by essentially concerted associative mechanisms, and it is demonstrated that two consecutive catalytic cycles need to be considered in order to determine the rate-determining free energy barrier. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Inorganic Chemistry
publisher
The American Chemical Society
external identifiers
  • pmid:26812142
  • scopus:84958780414
  • wos:000370395000060
ISSN
1520-510X
DOI
10.1021/acs.inorgchem.5b02733
language
English
LU publication?
yes
id
1cc620c3-786c-4c6d-8c5a-e32c630f3d85 (old id 8573608)
date added to LUP
2016-02-10 14:32:03
date last changed
2017-04-09 03:16:12
@article{1cc620c3-786c-4c6d-8c5a-e32c630f3d85,
  abstract     = {Density functional theory calculations have been used to investigate the reaction mechanisms of phosphodiester hydrolysis and transesterification catalyzed by a dinuclear zinc complex of the 2-(N-isopropyl-N-((2-pyridyl)methyl)aminomethyl)-6-(N-(carboxylmethyl)-N-((2-pyridyl)methyl)amino-methyl)-4-methylphenol (IPCPMP) ligand, mimicking the active site of zinc phosphotriesterase. The substrates bis(2,4)-dinitrophenyl phosphate (BDNPP) and 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) were employed as analogues of DNA and RNA, respectively. A number of different mechanistic proposals were considered, with the active catalyst harboring either one or two hydroxide ions. It is concluded that for both reactions the catalyst has only one hydroxide bound, as this option yields lower overall energy barriers. For BDNPP hydrolysis, it is suggested that the hydroxide acts as the nucleophile in the reaction, attacking the phosphorus center of the substrate. For HPNP transesterification, on the other hand, the hydroxide is proposed to act as a Brønsted base, deprotonating the alcohol moiety of the substrate, which in turn performs the nucleophilic attack. The calculated overall barriers are in good agreement with measured rates. Both reactions are found to proceed by essentially concerted associative mechanisms, and it is demonstrated that two consecutive catalytic cycles need to be considered in order to determine the rate-determining free energy barrier.},
  author       = {Daver, Henrik and Das, Biswanath and Nordlander, Ebbe and Himo, Fahmi},
  issn         = {1520-510X},
  language     = {eng},
  month        = {01},
  publisher    = {The American Chemical Society},
  series       = {Inorganic Chemistry},
  title        = {Theoretical Study of Phosphodiester Hydrolysis and Transesterification Catalyzed by an Unsymmetric Biomimetic Dizinc Complex.},
  url          = {http://dx.doi.org/10.1021/acs.inorgchem.5b02733},
  year         = {2016},
}