UV-induced electron transfer between triethylamine and 5-bromo-2′-deoxyuridine. A puzzle concerning the photochemical debromination of labeled DNA

X-ray and UV Radiation Damage of dsDNA/Protein Complexes

“…The last system subjected to the analysis was the BrdU labeled system. Within the LC-MS analysis, fragments (Figure 4) corresponding to the occurrence of the β-elimination (see Figure S9) process of the sugar of the adjacent nucleobase in the 5 direction (PU1, DU1, DU2) and elimination of the hydrogen atom from the deoxyribose molecule of the sensitizer nucleotide (PU2, DU5) were identified-which stays with the agreement with mechanisms proposed in the literature [13,22,23]. However, as in the case of the BrdU molecule, we can recognize the fragments responsible for elimination of the guanosine nucleoside (PU5, PU3, DU4, DU6).…”

“…In addition, we can distinguish that the labeled system is more resistant to 320 nm photons than 280 nm ones. This may be related to the tautomeric equilibrium, which changes the absorption spectrum of BrdG [ 23 ]. It is also important to mention that there were almost no degradation products identified by LC-MS analysis which goes alongside with the low degradation rate of BrdG labeled material, indicating low sensitivity of BrdG sensitizer to UV radiation.…”

“…It was shown that the most sensitive sequence to the PET process is 5′-GAABrU-3′ and sensitivity is highly dependent upon the DNA sequence between the electron donor and the acceptor [ 22 ]. It was also shown previously, that electron transfer can occur between the amines present in the surrounding BrdU molecule in DNA, thus we should consider all distinct molecules present in the DNA environment [ 23 ].…”

Polymerase Synthesis of DNA Containing Iodinated Pyrimidine or 7‐Deazapurine Nucleobases and Their Post‐synthetic Modifications through the Suzuki‐Miyaura Cross‐Coupling Reactions

“…Hence the enzymatic synthesis can be efficiently used for construction of single-stranded ONs or double stranded DNA containing one or multiple iodinated nucleobases at specific positions (either at the terminal or internal positions). The iodinated ONs or DNA can be used for diverse applications, including previously reported cross-linking [2][3][4][5][6][7][8][9][10][11][12][13][14][15] or some post-synthetic modifications.…”

“…5-Bromo-2'-deoxyuridine (BrdU) is used for metabolic labelling of DNA synthesis in combination with antibody detection. [1] Brominated as well as iodinated pyrimidines are photosensitive [2,3,4] and are frequently used for generation of pyrimidine radicals [5,6,7] in DNA that can form covalent cross-links with proteins [8][9][10][11][12][13][14][15] or with another DNA nucleobase, [16,17] or induce DNA strand breaks. [18,19] On the other hand, 7-iodinated 7-deazapurines are underrepresented in the literature with just few works reporting that both 7-iodo-7deazaadenine [20] and 7-iodo-7-deazaguanine [21,22] stabilize DNA duplexes.…”