%0 Journal Article
%T Radiolytic Reduction Characteristics of Artificial Oligodeoxynucleotides Possessing 2-Oxoalkyl Group or Disulfide Bonds
%A Kazuhito Tanabe
%A Takeo Ito
%A Sei-ichi Nishimoto
%J Journal of Nucleic Acids
%D 2011
%I Hindawi Publishing Corporation
%R 10.4061/2011/816207
%X A number of advances have been made in the development of modified oligodeoxynucleotides (ODNs), and chemical or physical properties of which are controlled by external stimuli. These intelligent ODNs are promising for the next generation of gene diagnostics and therapy. This paper focuses on the molecular design of artificial ODNs that are activated by X-irradiation and their applications to regulation of hybridization properties, conformation change, radiation-activated DNAzyme, and decoy molecules. 1. Introduction Regulation of chemical or physical properties of oligodeoxynucleotides (ODNs) is important for the development of future gene diagnostics and therapy [1, 2]. Because the function of ODNs is based on their conformation and hybridization properties with their complementary DNA or RNA, various attempts have been made to manipulate these basic characteristics using chemical modification and external stimuli [3¨C11]. These include the binding of a metal ion to mismatched [3, 4] or modified nucleobases [5, 6], interaction of boron compounds with modified riboses [7, 8], and photochemical methods that use nitrobenzene [9, 10] or azobenzene [11] functionalities on ODNs. High-energy ionizing radiation is an attractive stimulus for controlling the activity of biomaterials, because the radiation reaction can be controlled spatially and temporally without any additives [12, 13]. In particular, X-ray has potential because it has high live-body permeability, and thus, has been extensively used for medical treatment and diagnosis. In this paper, we describe the current state of research on controlling the function of ODNs by X-irradiation. This paper includes our recent research on the development of artificial ODNs possessing a 2-oxoalkyl group [14] or disulfide bonds [15, 16], whose properties and conformation can be regulated by X-irradiation. We applied their characteristics to regulation of hybridization, radiation-activated DNAzyme, regulation of the polymerase reaction, and conformation change of ODNs and decoy molecules for inhibition of protein-DNA interactions. When diluted aqueous solutions are irradiated, practically all of the absorbed energy is deposited in water molecules, and the observed chemical changes are brought about indirectly by the molecular and, in particular, the radical products of water radiolysis. It is well known that ionization and excitation of water molecules by ionizing radiation occur and generate electronically excited states (H2O*), radical cations (H2O+£¿), and dry electrons ( ). The excited water molecules H2O*
%U http://www.hindawi.com/journals/jna/2011/816207/