Is non-statistical dissociation a general feature of guanine–cytosine base-pair ions? Collision-induced dissociation of a protonated 9-methylguanine–1-methylcytosine Watson–Crick base pair, and comparison with its deprotonated and radical cation analogues

2020 ◽  
Vol 22 (43) ◽  
pp. 24986-25000
Author(s):  
Yan Sun ◽  
May Myat Moe ◽  
Jianbo Liu
Keyword(s):  
Radical Cation ◽  
Base Pair ◽  
General Feature ◽  
Collision Induced Dissociation

Non-statistical dissociation of a protonated guanine–cytosine Watson–Crick base pair.

Mass spectrometry and computational study of collision-induced dissociation of 9-methylguanine–1-methylcytosine base-pair radical cation: intra-base-pair proton transfer and hydrogen transfer, non-statistical dissociation, and reaction with a water ligand

2020 ◽  
Vol 22 (26) ◽  
pp. 14875-14888 ◽  
Author(s):  
Yan Sun ◽  
May Myat Moe ◽  
Jianbo Liu
Keyword(s):  
Mass Spectrometry ◽  
Proton Transfer ◽  
Radical Cation ◽  
Base Pair ◽  
Hydrogen Transfer ◽  
Theoretical Study ◽  
Computational Study ◽  
Collision Induced Dissociation ◽  
Water Ligand

A combined experimental and theoretical study is presented on the collision-induced dissociation of 9-methylguanine–1-methylcytosine base-pair radical cation ([9MG·1MC]˙+) and its monohydrate ([9MG·1MC]˙+·H2O) with Xe and Ar gases.

External electric field promotes proton transfer in the radical cation of adenine–thymine

2016 ◽  
Vol 30 (21) ◽  
pp. 1650276 ◽  
Author(s):  
Guiqing Zhang ◽  
Shijie Xie
Keyword(s):  
Electric Field ◽  
Proton Transfer ◽  
External Electric Field ◽  
Radical Cation ◽  
Base Pair ◽  
Low Temperatures ◽  
Room Temperature ◽  
Theoretical Calculations ◽  
Base Pairs ◽  
Adenine Thymine

According to [Formula: see text] measurements, it has been predicted that proton transfer would not occur in the radical cation of adenine–thymine (A:T). However, recent theoretical calculations indicate that proton transfer takes place in the base pair in water below the room temperature. We have performed simulations of proton transfer in the cation of B-DNA stack composed of 10 A:T base pairs in water from 20 K to 300 K. Proton transfer occurs below the room temperature, meanwhile it could also be observed at the room temperature under the external electric field. Another case that interests us is that proton transfer bounces back after [Formula: see text][Formula: see text]300 fs from the appearance of proton transfer at low temperatures.

Hydrogen atom transfer in the radical cations of tryptophan-containing peptides AW and WA studied by mass spectrometry, infrared multiple-photon dissociation spectroscopy, and theoretical calculations

2018 ◽  
Vol 25 (1) ◽  
pp. 112-121 ◽  
Author(s):  
Andrii Piatkivskyi ◽  
Justin Kai-Chi Lau ◽  
Giel Berden ◽  
Jos Oomens ◽  
Alan C Hopkinson ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Gas Phase ◽  
Radical Cation ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Radical Cations ◽  
Hydrogen Atom Transfer ◽  
Collision Induced Dissociation ◽  
Infrared Multiple Photon Dissociation ◽  
Nitrogen Radical

Two types of radical cations of tryptophan—the π-radical cation and the protonated tryptophan-N radical—have been studied in dipeptides AW and WA. The π-radical cation produced by removal of an electron during collision-induced dissociation of a ternary Cu(II) complex was only observed for the AW peptide. In the case of WA, only the ion corresponding to the loss of ammonia, [WA–NH3] •+, was observed from the copper complex. Both protonated tryptophan-N radicals were produced by N-nitrosylation of the neutral peptides followed by transfer to the gas phase via electrospray ionization and subsequent collision-induced dissociation. The regiospecifically formed N• species were characterized by infrared multiple-photon dissociation spectroscopy which revealed that the WA tryptophan-N• radical remains the nitrogen radical, while the AW nitrogen radical rearranges into the π-radical cation. These findings are supported by the density functional theory calculations that suggest a relatively high barrier for the radical rearrangement (N• to π) in WA (156.3 kJ mol−1) and a very low barrier in AW (6.1 kJ mol−1). The facile hydrogen atom migration in the AW system is also supported by the collision-induced dissociation of the tryptophan-N radical species that produces fragments characteristic of the tryptophan π-radical cation. Gas-phase ion–molecule reactions with n-propyl thiol have also been used to differentiate between the π-radical cations (react by hydrogen abstraction) and the tryptophan-N• species (unreactive) of AW.

scholarly journals Gas-phase structure and reactivity of the keto tautomer of the deoxyguanosine radical cation

2015 ◽  
Vol 17 (39) ◽  
pp. 25837-25844 ◽  
Author(s):  
Linda Feketeová ◽  
Bun Chan ◽  
George N. Khairallah ◽  
Vincent Steinmetz ◽  
Philippe Maître ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Computational Chemistry ◽  
Gas Phase ◽  
Radical Cation ◽  
Phase Structure ◽  
Collision Induced Dissociation ◽  
Ion Molecule Reactions ◽  
Gas Phase Structure

Gas-phase IR spectroscopy, ion–molecule reactions, collision-induced dissociation and computational chemistry in combination form a powerful tool to gain insights into the structure of one-electron oxidised guanine in DNA and its resultant chemistry.

Dissociation of the Anthracene Radical Cation: A Comparative Look at iPEPICO and Collision-Induced Dissociation Mass Spectrometry Results

2014 ◽  
Vol 118 (42) ◽  
pp. 9870-9878 ◽  
Author(s):  
Brandi West ◽  
Alicia Sit ◽  
Sabria Mohamed ◽  
Christine Joblin ◽  
Valerie Blanchet ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Radical Cation ◽  
Collision Induced Dissociation

Watson–Crick Base Pair Radical Cation as a Model for Oxidative Damage in DNA

2017 ◽  
Vol 8 (13) ◽  
pp. 3159-3165 ◽  
Author(s):  
Linda Feketeová ◽  
Bun Chan ◽  
George N. Khairallah ◽  
Vincent Steinmetz ◽  
Philippe Maitre ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Radical Cation ◽  
Base Pair

Isomerization versus dissociation of phenylalanylglycyltryptophan radical cations

2017 ◽  
Vol 19 (25) ◽  
pp. 16923-16933 ◽  
Author(s):  
Xiaoyan Mu ◽  
Justin Kai-Chi Lau ◽  
Cheuk-Kuen Lai ◽  
K. W. Michael Siu ◽  
Alan C. Hopkinson ◽  
...  
Keyword(s):  
Radical Cation ◽  
Radical Cations ◽  
Collision Induced Dissociation ◽  
Radical Center ◽  
Initial Location

Four isomers of the radical cation of tripeptide phenylalanylglycyltryptophan, in which the initial location of the radical center is well defined, have been isolated and their collision-induced dissociation (CID) spectra examined.

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