QM and QM/MM umbrella sampling MD study of the formation of Hg(II)–thymine bond: Model for evaluation of the reaction energy profiles in solutions with constant pH
The formation of the Hg–N3(T) bond between the 1‐methylthymine (T) molecule and the hydrated Hg2+ cation was explored with the combined quantum mechanics/molecular mechanics (QM/MM) method including Free Energy Perturbation corrections. The thermodynamic properties were determined in the whole pH ra...
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| Vydáno v: | Journal of computational chemistry Ročník 41; číslo 16; s. 1509 - 1520 |
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| Hlavní autoři: | , , , , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
Hoboken, USA
John Wiley & Sons, Inc
15.06.2020
Wiley Subscription Services, Inc |
| Témata: | |
| ISSN: | 0192-8651, 1096-987X, 1096-987X |
| On-line přístup: | Získat plný text |
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| Shrnutí: | The formation of the Hg–N3(T) bond between the 1‐methylthymine (T) molecule and the hydrated Hg2+ cation was explored with the combined quantum mechanics/molecular mechanics (QM/MM) method including Free Energy Perturbation corrections. The thermodynamic properties were determined in the whole pH range, when these systems were explicitly investigated and considered as the QM part: (1) T + [Hg(H2O)6]2+, (2) T + [Hg(H2O)5(OH)]+, (3) T + Hg(H2O)4(OH)2, and (4) N3‐deprotonated T + Hg(H2O)4(OH)2. The MM part contained only solvent molecules and counterions. As a result, the dependence of Gibbs‐Alberty reaction free energy on pH was obtained along the reaction coordinate. We found that an endoergic reaction in acidic condition up to pH < 4–5 becomes exoergic for a higher pH corresponding to neutral and basic solutions. The migration of the Hg2+ cation between N3 and O4/2 positions in dependence on pH is discussed as well. For the verification, DFT calculations of stationary points were performed confirming the qualitative trends of QM/MM MD simulations and NMR parameters were determined for them. |
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| Bibliografie: | Funding information Grant Agency of Czech Republic, Grant/Award Numbers: 16‐06240S, 18‐14990S; National Grid Infrastructure MetaCentrum, Grant/Award Number: LM2010005; Grant Agency of Charles University, Grant/Award Number: 1145016 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 |
| ISSN: | 0192-8651 1096-987X 1096-987X |
| DOI: | 10.1002/jcc.26194 |