title: Formation of 8-S-L-cysteinylguanosine from 8-bromoguanosine and cysteine.
abstract: When 8-bromoguanosine was incubated with cysteine at pH 7.4 and 37 °C, a previously unidentified product was formed as a major product in addition to guanosine. The product was identified as a cysteine substitution derivative of guanosine at the 8 position, 8-S-L-cysteinylguanosine. The reaction was accelerated under mildly basic conditions. The cysteine adduct of guanosine was fairly stable and decomposed with a half-life of 193 h at pH 7.4 and 37 °C. Similar results were observed for incubation of 8-bromo-2'-deoxyguanosine with cysteine. The results suggest that 8-bromoguanine in nucleosides, nucleotides, RNA, and DNA can react with thiols resulting in stable adducts.
authors.affiliation: School of Pharmacy, Shujitsu University, Okayama 703-8516, Japan. tsuzuki@shujitsu.ac.jp
authors.forename: Toshinori
authors.initials: T
authors.lastname: Suzuki
authors.forename: Aya
authors.initials: A
authors.lastname: Kosaka
authors.forename: Michiyo
authors.initials: M
authors.lastname: Inukai
mesh_terms: D003545:Cysteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D006151:Guanosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D013696:Temperature; D013997:Time Factors
chemical_list: C585541:8-S-L-cysteinylguanosine; D006151:Guanosine; C035169:8-bromoguanosine; D003545:Cysteine