Thus a single pyrimidine dimer
, if left unrepaired, is sufficient to completely eliminate the expression of a transcriptional unit.
Simultaneous establishment of monoclonal antibodies specific for either cyclobutane pyrimidine dimer
or (6-4) photoproduct from the same mouse immunized with ultraviolet-irradiated DNA.
DNA was obtained from plants that were not exposed to UV, with the following exceptions: pea seedlings from the greenhouse, soybean leaves from field-grown plants, and rice seedlings exposed to UV in the laboratory for measurement of pyrimidine dimer
Ultraviolet radiation disrupts the structure of DNA by causing a chemical reaction that hooks together two distinct bases, forming a so-called pyrimidine dimer
Specifically, niacinamide is known to enhance DNA excision repair and repair of UVB-induced cyclobutane pyrimidine dimers
and UVA-induced 8-oxo-7,8-dihydro-2'-deoxyguanosine.
Subsequent exposure to photo-reactivating light decreased the number of pyrimidine dimers
Scientists found that Polypodium leucotomos, orally administered to hairless mice before UV radiation, inhibited DNA damage, activated p53, increased removal of cyclobutane pyrimidine dimers
, and reduced the number of 8-hydroxy-2'-deoxyguanosinepositive (8-OH-dG+) cells, which are markers of early DNA damage.
UVB and UVC light induce the formation of cyclobutane pyrimidine dimers
(CPDs) and pyrimidine(6-4)pyrimidone photoproducts (6-4 PPs), whereas UVA light primarily causes oxidative DNA damage via the formation of 8-oxo-7,8-dihydroguanine (8-oxoG) and cyclobutane thymidine dimers [5, 6], potentially leading to single-strand breaks and other interstrand cross-links (ICLs) in DNA .
Reagentas cyclobutane pyrimidine dimers
determination after UV-irradiation preliminary points to 1 Coll .
Further studies, performed mainly at Stanford University, revealed that the phage T4 enzymes specifically and uniquely incise DNA containing photoproducts called pyrimidine dimers
A decrease in pyrimidine dimers
, in 18 out of 19 patients, for an average reduction of 53%.
14 T4 endonuclease V has been shown to repair cyclobutane pyrimidine dimers
resulting from DNA damage.