Fast protonation of adenosine and of its radical anion formed by hydrated electron attack; a nanosecond optical and dc-conductivity pulse radiolysis study.
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.
Visscher
K J
KJ
Department of Biophysics, Vrije Universiteit, Amsterdam, The Netherlands.
de Haas
M P
MP
Loman
H
H
Vojnovic
B
B
Warman
J M
JM
D000241:Adenosine; D000838:Anions; D003839:Deoxyadenosines; D004583:Electrons; D011522:Protons; D011675:Pulse Radiolysis / Q000379:methods; D012996:Solutions; D013997:Time Factors; D014867:Water
D000838:Anions; D003839:Deoxyadenosines; D011522:Protons; D012996:Solutions; D014867:Water; D000241:Adenosine