O4 -Alkylated-2-Deoxyuridine Repair by O6 -Alkylguanine DNA Alkyltransferase is Augmented by a C5-Fluorine Modification.
Lauralicia SacreDerek K O'FlahertyPhilippe ArchambaultWilliam CoppGilles H PeslherbeHeidi M MuchallChristopher J WildsPublished in: Chembiochem : a European journal of chemical biology (2018)
Oligonucleotides containing various adducts, including ethyl, benzyl, 4-hydroxybutyl and 7-hydroxyheptyl groups, at the O4 atom of 5-fluoro-O4 -alkyl-2'-deoxyuridine were prepared by solid-phase synthesis. UV thermal denaturation studies demonstrated that these modifications destabilised the duplex by approximately 10 °C, relative to the control containing 5-fluoro-2'-deoxyuridine. Circular dichroism spectroscopy revealed that these modified duplexes all adopted a B-form DNA structure. O6 -Alkylguanine DNA alkyltransferase (AGT) from humans (hAGT) was most efficient at repair of the 5-fluoro-O4 -benzyl-2'-deoxyuridine adduct, whereas the thymidine analogue was refractory to repair. The Escherichia coli AGT variant (OGT) was also efficient at removing O4 -ethyl and benzyl adducts of 5-fluoro-2-deoxyuridine. Computational assessment of N1-methyl analogues of the O4 -alkylated nucleobases revealed that the C5-fluorine modification had an influence on reducing the electron density of the O4 -Cα bond, relative to thymine (C5-methyl) and uracil (C5-hydrogen). These results reveal the positive influence of the C5-fluorine atom on the repair of larger O4 -alkyl adducts to expand knowledge of the range of substrates able to be repaired by AGT.
Keyphrases
- positron emission tomography
- computed tomography
- single molecule
- circulating tumor
- escherichia coli
- ionic liquid
- cell free
- pet imaging
- single cell
- pet ct
- nucleic acid
- healthcare
- molecular dynamics
- gene expression
- high resolution
- staphylococcus aureus
- cystic fibrosis
- biofilm formation
- dna methylation
- circulating tumor cells
- mass spectrometry
- candida albicans