title: Fast protonation of adenosine and of its radical anion formed by hydrated electron attack; a nanosecond optical and dc-conductivity pulse radiolysis study.
abstract: The study of the reaction of the hydrated electron with adenosine by optical and dc-conductivity pulse radiolysis on nano- and microsecond timescales has been carried out in an attempt to answer the question whether the electron adduct radical becomes protonated or not. The following conclusions have been reached: (1) the reaction of the hydrated electron with adenosine is followed by a water-mediated protonation, which must be complete with 5 ns; (2) no spectral indication of a further protonation of the protonated electron adduct of adenosine of 2'-deoxyadenosine has been found between 40 and 5000 ns; (3) the equilibrium reaction between radiation produced H3O+ and adenosine with a pKa of 3.5 plays an important role in the kinetics of the conductivity transients.
authors.affiliation: Department of Biophysics, Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: K J
authors.initials: KJ
authors.lastname: Visscher
authors.forename: M P
authors.initials: MP
authors.lastname: de Haas
authors.forename: H
authors.initials: H
authors.lastname: Loman
authors.forename: B
authors.initials: B
authors.lastname: Vojnovic
authors.forename: J M
authors.initials: JM
authors.lastname: Warman
mesh_terms: D000241:Adenosine; D000838:Anions; D003839:Deoxyadenosines; D004583:Electrons; D011522:Protons; D011675:Pulse Radiolysis / Q000379:methods; D012996:Solutions; D013997:Time Factors; D014867:Water
chemical_list: D000838:Anions; D003839:Deoxyadenosines; D011522:Protons; D012996:Solutions; D014867:Water; D000241:Adenosine