Measurement of deaminated cytosine adducts in DNA using a novel hybrid thymine DNA glycosylase

• DOI: 10.1016/j.jbc.2022.101638
• Publication Date: 2022-01-25T01:47:51Z
• Authors: Chia Wei Hsu; Mark L. Sowers; Tuvshintugs Balji...; Jason L. Herring; Linda C. Hackfeld; Hui Tang; Kangling Zhang; Lawrence C. Sowers
• Keywords: Cytosine; Thymine; Deamination

The hydrolytic deamination of cytosine and 5-methylcytosine drives many the transition mutations observed in human cancer. deamination-induced mutagenic intermediates include either uracil or thymine adducts mispaired with guanine. While a substantial array methods exist to measure other types DNA adducts, pose unusual analytical problems, adequate them have not yet been developed. We describe here novel hybrid glycosylase (TDG) that is comprised 29-amino acid sequence from TDG linked catalytic domain found an archaeal thermophilic bacterium. Using defined-sequence oligonucleotides, we show has robust mispair-selective activity against deaminated U:G T:G mispairs. further developed method for separating glycosylase-released free bases oligonucleotides followed by GC-MS/MS quantification. this approach, measured first time levels total uracil, U:G, pairs calf thymus DNA. presented will allow measurement formation, persistence, repair biologically important class adducts.