Base pair electron affinities

Russo N, Toscano M, Grand A (2000) Theoretical determination of electron affinity and ionization potential of DNAand RNA bases. J Comput Chem 21 1243-1250 Sagstuen E, Hole EO, Nelson WH, Close DM (1998) Radiation damage to DNA base pairs. II. Paramagnetic resonance studies of 1 -methyluracil. 9-ethyladenine complex crystals X-irradiated at 10 K. Radiat Res 149 120-127... 

Lewis FD, Letsinger RL, Wasielewski MR (2001) Dynamics of photoinduced charge transfer and hole transport in synthetic DNA hairpins. Acc Chem Res 34 159-170 Li Z, Cai Z, Sevilla MD (2001) Investigation of proton transfer within DNA base pair anion and cation radicals by density functional theory (DFT).J Phys Chem B 105 10115-10123 Li Z, Cai Z, Sevilla MD (2002) DFT calculations on the electron affinities of nucleic acid bases dealing with negative electron affinities. J Phys Chem A 106 1596-1603 Lillicrap SC, Fielden EM (1969) Luminescence kinetics following pulse irradiation. II. DNA. J Chem Phys 51 3503-3511... 

Electron transport through DNA, in which electron hopping involves radical anions of base pairs, is less likely to occur than hole hopping, involving radical cations, because the DNA bases have weak electron affinities 166 consequently, the energies of the anionic states of base pairs, in general, he well above those of conventional donor and acceptor chromophores. 

Gas Phase Electron Affinities of DNA Bases and Base pairs (Valence and Diffuse States)... 

Table 20-8. Gas phase electron affinities (eV) of AT and GC base pairs derived from experiment and different theoretical methods...

Effect of Solvation on the Electron Affinity (EA) of Bases and Base Pairs... 

Table 20-9. Adiabatic electron affinities (AEAs) of T, C, U, G and AT base pair in solution using different methods and basis set...

As a consequence of base pairing, only a limited number of possible metal-binding sites in the bases are available in duplexes even fewer sites are accessible in triplex and quadruplex structures (Figure 2). The electron density of donor atoms that remain available for metal binding also differs from the electron density in isolated base residues. For example, the affinity of purine N-7 and N-3 atoms for... 

In the relevant experiment to determine electron transfer, the DNA intercalator mitoxantrone (MX) is used. MX binds well to DNA and has a high electron affinity. MX appears to intercalate randomly if used at an intercalator base-pair ratio of 1/20 or less. In a 7-M LiBr glass at 77 K, /-irradiation produces electrons that attach randomly onto the DNA and MX, and the holes are... 

---