10.1021/acs.jpca.7b08334.s001
Michał A. Kochman
Michał A.
Kochman
Andrzej Bil
Andrzej
Bil
R. J. Dwayne Miller
R.
J. Dwayne Miller
Mechanism Underlying the Nucleobase-Distinguishing
Ability of Benzopyridopyrimidine (BPP)
American Chemical Society
2017
adenine causes
site
selectivity
base pairs
quenching process
CT state
nucleobase analogue
computer simulations
Benzopyridopyrimidine
guanine
Nucleobase-Distinguishing Ability
charge transfer
electron affinity
CT process
BPP-G base pair
fluorescence quantum
purine nucleobases
purine nucleobase
charge acceptor
BPP-A base pair
photoinduced CT processes
2017-10-06 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Mechanism_Underlying_the_Nucleobase-Distinguishing_Ability_of_Benzopyridopyrimidine_BPP_/5514718
Benzopyridopyrimidine
(BPP) is a fluorescent nucleobase analogue
capable of forming base pairs with adenine (A) and guanine (G) at
different sites. When incorporated into oligodeoxynucleotides, it
is capable of differentiating between the two purine nucleobases by
virtue of the fact that its fluorescence is largely quenched when
it is base-paired to guanine, whereas base-pairing to adenine causes
only a slight reduction of the fluorescence quantum yield. In the
present article, the photophysics of BPP is investigated through computer
simulations. BPP is found to be a good charge acceptor, as demonstrated
by its positive and appreciably large electron affinity. The selective
quenching process is attributed to charge transfer (CT) from the purine
nucleobase, which is predicted to be efficient in the BPP-G base pair,
but essentially inoperative in the BPP-A base pair. The CT process
owes its high selectivity to a combination of two factors: the ionization
potential of guanine is lower than that of adenine, and less obviously,
the site occupied by guanine enables a greater stabilization of the
CT state through electrostatic interactions than the one occupied
by adenine. The case of BPP illustrates that molecular recognition
via hydrogen bonding can enhance the selectivity of photoinduced CT
processes.