A QM/QTAIM microstructural analysis of the tautomerisation via the DPT of the hypoxanthine•adenine nucleobase pair

被引：20

作者：

Brovarets, Ol'ha O. ^{[1
,2
,3
]}

Zhurakivsky, Roman O. ^{[1
,2
]}

Hovorun, Dmytro M. ^{[1
,2
,3
]}

机构：

[1] Natl Acad Sci Ukraine, Dept Mol & Quantum Biophys, Inst Mol Biol & Genet, Kiev, Ukraine

[2] Res & Educ Ctr, State Key Lab Mol & Cell Biol, Kiev, Ukraine

[3] Taras Shevchenko Natl Univ Kyiv, Inst High Technol, Dept Mol Biotechnol & Bioinformat, Kiev, Ukraine

来源：

MOLECULAR PHYSICS | 2014年 / 112卷 / 15期

关键词：

keto and enol tautomers of the hypoxanthine; amino and imino tautomers of the adenine; hypoxanthine center dot adenine base pair; sweeps of the energetic; electron-topological; geometric; polar and NBO parameters along the IRC; the double proton transfer; cooperativity of the H-bonds; B3LYP and MP2 levels of QM theory; QTAIM analysis; MOLECULAR-ORBITAL METHODS; SET SUPERPOSITION ERROR; CRICK BASE-PAIR; AB-INITIO; MUTAGENIC TAUTOMERS; BONDED COMPLEXES; IMINO TAUTOMERS; HYDROGEN-BONDS; HARTREE-FOCK; GAS-PHASE;

D O I：

10.1080/00268976.2013.877170

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We provide a pathway for the tautomerisation of the biologically important hypoxanthine adenine (Hyp center dot Ade) nucleobase pair (C-s) formed by the keto tautomer of the Hyp and the amino tautomer of the Ade into the Hyp*center dot Ade* base pair (Cs) formed by the enol tautomer of the Hyp and the imino tautomer of the Ade by applying quantum-mechanical calculations and Bader's Quantum Theory of Atoms in Molecules analysis. It was found out that the dipole active Hyp center dot Ade <-> Hyp*center dot Ade* tautomerisation occurs via the asynchronous concerted double proton transfer (DPT) through the TSHyp center dot Ade <-> Hyp*center dot Ade* (Cs). Based on the sweeps of the energies of the intermolecular H-bonds along the intrinsic reaction coordinate, it was established that the N6H center dot center dot center dot O6 H-bond (5.40) is cooperative with the N1H center dot center dot center dot N1 H-bond (6.99) in the Hyp Ade base pair, as well as the O6H center dot center dot center dot N6 H-bond (11.50) is cooperative with the N1H center dot center dot center dot N1 H-bond (7.28 kcal mol(-1)) in the Hyp*center dot Ade* base pair, mutually strengthening each other. The Hyp*center dot Ade* base pair possesses an extremely short lifetime 2.68.10(-14) s, which is predetermined by the negative value of the Gibbs free energy of the reverse barrier of its tautomerisation, and all of the six low-frequency intermolecular vibrations cannot develop during this period of time. Consequently, the Hyp center dot Ade -> Hyp*center dot Ade* DPT tautomerisation cannot serve as a source of the rare tautomers of the bases.

引用

页码：2005 / 2016

页数：12

共 101 条

[1]

[Anonymous], 2011, Newnes

[2]

[Anonymous], J BIOMOLECULAR STRUC

[3]

[Anonymous], ADV QUANTUM CHEM, DOI DOI 10.1016/S0065-3276(08)60076-3

[4]

[Anonymous], 2012, QUANTUM CHEM MOL INN