Photoinduced Electron Detachment and Proton Transfer: The Proposal for Alternative Path of Formation of Triplet States of Guanine (G) and Cytosine (C) Pair

doi:10.1021/jp507385r

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	Photoinduced Electron Detachment and Proton Transfer: The Proposal for Alternative Path of Formation of Triplet States of Guanine (G) and Cytosine (C) Pair
	Gu, Jiande1 ; Wang, Jing 2; Leszczynski, Jerzy 2
刊名	JOURNAL OF PHYSICAL CHEMISTRY B
	2015-02-12
卷号	119 期号:6 页码:2454-2458
ISSN号	1520-6106
DOI	10.1021/jp507385r
文献子类	Article
英文摘要	A viable pathway is proposed for the formation of the triplet state of the GC WatsonCrick base pair. It includes the following steps: (a) a low-energy electron is captured by cytosine in the GC pair, forming the cytosine base-centered radical anion GC(-center dot); and (b) photoradiation with energy around 5 eV initiates the electron detachment from either cytosine (in the gas phase) or guanine (in aqueous solutions). This triggers interbase proton transfer from G to C, creating the triplet state of the GC pair. Double proton transfer involving the triplet state of GC pair leads to the formation of less stable tautomer G(N2H)C-center dot(O2H)(center dot). Tautomerization is accomplished through a double proton transfer process in which one proton at the N3 of C(H)(center dot) migrates to the N1 of G(-H)(center dot); meanwhile, the proton at the N2 of G transfers to the O2 of C. This process is energetically viable; the corresponding activation energy is around 1213 kcal/mol. The base-pairing energy of the triplet is found to be similar to 35 kcal/mol smaller than that of the singlet state. Thus, the formation of the triplet state GC pair in DNA double strand only slightly weakens its stability. The obtained highly reactive radicals are expected to cause serious damage in the DNA involved in biochemical processes, such as DNA replication where radicals are exposed in the single strands.
资助项目	NSF[CHE1004570] ; NASA Astrobiology Program under NSF Center for Chemical Evolution[CHE1004570]
WOS关键词	LOW-ENERGY ELECTRONS ; FUNCTIONAL THEORY DFT ; THYMINE BASE-PAIR ; DENSITY FUNCTIONALS ; ADENINE-THYMINE ; PHOTOELECTRON-SPECTROSCOPY ; LOSS DISTRIBUTIONS ; PYRIMIDINE-BASES ; AQUEOUS-SOLUTION ; RADICAL-ANIONS
WOS研究方向	Chemistry
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000349578600036
内容类型	期刊论文
源URL	[http://119.78.100.183/handle/2S10ELR8/276641]
专题	药物发现与设计中心中科院受体结构与功能重点实验室新药研究国家重点实验室
通讯作者	Gu, Jiande
作者单位	1.Chinese Acad Sci, Drug Design & Discovery Ctr, State Key Lab Drug Res, Shanghai Inst Mat Med, Shanghai 201203, Peoples R China; 2.Jackson State Univ, Dept Chem, Interdisciplinary Nanotox Ctr, Jackson, MS 39217 USA
推荐引用方式 GB/T 7714	Gu, Jiande,Wang, Jing,Leszczynski, Jerzy. Photoinduced Electron Detachment and Proton Transfer: The Proposal for Alternative Path of Formation of Triplet States of Guanine (G) and Cytosine (C) Pair[J]. JOURNAL OF PHYSICAL CHEMISTRY B,2015,119(6):2454-2458.
APA	Gu, Jiande,Wang, Jing,&Leszczynski, Jerzy.(2015).Photoinduced Electron Detachment and Proton Transfer: The Proposal for Alternative Path of Formation of Triplet States of Guanine (G) and Cytosine (C) Pair.JOURNAL OF PHYSICAL CHEMISTRY B,119(6),2454-2458.
MLA	Gu, Jiande,et al."Photoinduced Electron Detachment and Proton Transfer: The Proposal for Alternative Path of Formation of Triplet States of Guanine (G) and Cytosine (C) Pair".JOURNAL OF PHYSICAL CHEMISTRY B 119.6(2015):2454-2458.