Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (11): 3067-3072.doi: 10.3866/PKU.WHXB20101106

• QUANTUM CHEMISTRY AND COMPUTATION CHEMISTRY • Previous Articles     Next Articles

Effects of CH3OH and NH3 on the Hydrolytic Deamination Mechanismof Adenine

LIU Hai-Ying1, MENG Fan-Cui2, LI Ping1, DING Shi-Liang3   

  1. 1. School of Science, University of Jinan, Jinan 250022, P. R. China;
    2Tianjin Institute of Pharmaceutical Research, Tianjin 300193, P. R. China;
    3School of Physics, Shandong University, Jinan 250100, P. R. China
  • Received:2010-04-27 Revised:2010-08-10 Published:2010-10-29
  • Contact: LIU Hai-Ying E-mail:chinayidu@yahoo.com.cn
  • Supported by:

    The project was supported by the Ph.D. Foundation of Shandong Province, China (2008BS02014) and Scientific Research Foundation of University of Jinan, China (XKY0809).

Abstract:

The effects of CH3OH and NH3 on the hydrolytic deamination mechanism of adenine were studied by density functional theory at the B3LYP/6-311G(d,p) level. The results reveal that a tetrahedral intermediate is formed after a nucleophilic attack by a water molecule. Two intermediates are formed through conformational changes and different pathways are responsible. In pathway a, an assistant molecule takes part in the formation of the transition state and acts as a bridge to transfer a hydrogen atom, while in pathway b the assistant molecule is not involved in the creation of the transition state and acts only as a medium. The adenine takes place an amine-imine tautomerization before the nucleophilic attack under NH3, which is not the case for the methanol-assisted mechanism. Energy results indicate that the energy barrier of the methanol-assisted adenine deamination is similar to that of the water-assisted reaction while the ammonia-assisted reaction has amuch higher energy barrier compared with the water-assisted reaction.

 

Key words: Adenine deamination, B3LYP, G3MP2, Ammonia-assistance, Methanol-assistance

MSC2000: 

  • O641