Structural and Electronic Properties of Adenine-Thymine Basepair : A Computational Study

It is well known that stability of deoxyribo-nucleic acid (DNA) double helix depends on hydrogen bonding (HB) between adenine-thymine and guanine-cytosine. HB plays an important role in molecular systems, particularly in biological systems because all lives on the earth may be viewed as a matter of hydrogen-bonding supramolecular systems. Since HBs have a central role on the mechanism of life phenomena including the structure and functions, it is essential to understand the molecular-level aspects of HB systems. Therefore, we studied the structural properties of adenine-thymine (A-T) basepair theoretically using DFT/B3LYP/6-31G level of theory. Theoretically we found four isomers of A-T basepair and the most stable isomer is one in which adenine and thymine are connected via two hydrogen bonding. The electronic properties were calculated by Time Dependent Density Functional Theory (TD-DFT) approach. Dhaka Univ. J. Sci. 67(1): 51-54, 2019 (January)

[1]  T. Bredow,et al.  A Theoretical Investigation of the Structural, Spectroscopic and Optical Properties of Adenine , 2016 .

[2]  Daniele Varsano,et al.  Optical properties of triplex DNA from time-dependent density functional theory. , 2012, The journal of physical chemistry. B.

[3]  Szu-Hsueh Lai,et al.  Disentangling intrinsic ultrafast excited-state dynamics of cytosine tautomers. , 2011, The journal of physical chemistry. A.

[4]  T. Elsaesser,et al.  Ultrafast Vibrational Dynamics and Local Interactions of Hydrated DNA , 2010 .

[5]  R. Improta,et al.  DNA/RNA: Building Blocks of Life Under UV Irradiation , 2010 .

[6]  Yu Kay Law,et al.  DNA excited-state dynamics: from single bases to the double helix. , 2009, Annual review of physical chemistry.

[7]  John M Herbert,et al.  Both intra- and interstrand charge-transfer excited states in aqueous B-DNA are present at energies comparable to, or just above, the (1)pipi* excitonic bright states. , 2009, Journal of the American Chemical Society.

[8]  W. Kwok,et al.  A doorway state leads to photostability or triplet photodamage in thymine DNA. , 2008, Journal of the American Chemical Society.

[9]  Á. Rubio,et al.  A TDDFT study of the excited states of DNA bases and their assemblies. , 2006, The journal of physical chemistry. B.

[10]  I. Hertel,et al.  Dynamics of photoinduced processes in adenine and thymine base pairs. , 2005, Journal of the American Chemical Society.

[11]  Benjamin Tardivel,et al.  Excited states dynamics of DNA and RNA bases: characterization of a stepwise deactivation pathway in the gas phase. , 2005, The Journal of chemical physics.

[12]  A. Stolow,et al.  Direct observation of electronic relaxation dynamics in adenine via time-resolved photoelectron spectroscopy. , 2004, Journal of the American Chemical Society.

[13]  Hyuk Kang,et al.  Intrinsic lifetimes of the excited state of DNA and RNA bases. , 2002, Journal of the American Chemical Society.

[14]  Wolfgang Domcke,et al.  On the mechanism of nonradiative decay of DNA bases: ab initio and TDDFT results for the excited states of 9H-adenine , 2002 .

[15]  H. Nakatsuji,et al.  Excited and ionized states of aniline: Symmetry adapted cluster configuration interaction theoretical study , 2002 .

[16]  B. Kohler,et al.  DNA excited-state dynamics: ultrafast internal conversion and vibrational cooling in a series of nucleosides. , 2001, Journal of the American Chemical Society.

[17]  E. Kool,et al.  Hydrogen bonding, base stacking, and steric effects in dna replication. , 2001, Annual review of biophysics and biomolecular structure.