scholarly journals Quantum and classical effects in DNA point mutations: Watson–Crick tautomerism in AT and GC base pairs

2021 ◽  
Vol 23 (7) ◽  
pp. 4141-4150
Author(s):  
L. Slocombe ◽  
J. S. Al-Khalili ◽  
M. Sacchi
Keyword(s):  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Gene Mutation ◽  
Point Mutations ◽  
Base Pairs ◽  
Biologically Relevant ◽  
Relevant Point ◽  
The Creation

Proton transfer along the hydrogen bonds of DNA can lead to the creation of short-lived, but biologically relevant point mutations that can further lead to gene mutation and, potentially, cancer.

Transient proton transfer of base pair hydrogen bonds induced by intense terahertz radiation

2020 ◽  
Vol 22 (17) ◽  
pp. 9316-9321
Author(s):  
Kaicheng Wang ◽  
Lixia Yang ◽  
Shaomeng Wang ◽  
Lianghao Guo ◽  
Jialu Ma ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Terahertz Radiation ◽  
Base Pair ◽  
Quantum Simulation ◽  
Base Pairs ◽  
Dna Base ◽  
Dna Base Pairs

Intense terahertz radiation was applied to trigger transient proton transfer in DNA base pairs through quantum simulation.

scholarly journals The influence of base pair tautomerism on single point mutations in aqueous DNA

2020 ◽  
Vol 10 (6) ◽  
pp. 20190120
Author(s):  
A. Gheorghiu ◽  
P. V. Coveney ◽  
A. A. Arabi
Keyword(s):  
Proton Transfer ◽  
Base Pair ◽  
Single Point ◽  
Point Mutations ◽  
Base Pairs ◽  
Single Proton ◽  
Double Proton Transfer ◽  
Wide Range ◽  
Single Point Mutations ◽  
The Double Proton Transfer

The relationship between base pair hydrogen bond proton transfer and the rate of spontaneous single point mutations at ambient temperatures and pressures in aqueous DNA is investigated. By using an ensemble-based multiscale computational modelling method, statistically robust rates of proton transfer for the A:T and G:C base pairs within a solvated DNA dodecamer are calculated. Several different proton transfer pathways are observed within the same base pair. It is shown that, in G:C, the double proton transfer tautomer is preferred, while the single proton transfer process is favoured in A:T. The reported range of rate coefficients for double proton transfer is consistent with recent experimental data. Notwithstanding the approximately 1000 times more common presence of single proton transfer products from A:T, observationally there is bias towards G:C to A:T mutations in a wide range of living organisms. We infer that the double proton transfer reactions between G:C base pairs have a negligible contribution towards this bias for the following reasons: (i) the maximum half-life of the G*:C* tautomer is in the range of picoseconds, which is significantly smaller than the milliseconds it takes for DNA to unwind during replication, (ii) statistically, the majority of G*:C* tautomers revert back to their canonical forms through a barrierless process, and (iii) the thermodynamic instability of the tautomers with respect to the canonical base pairs. Through similar reasoning, we also deduce that proton transfer in the A:T base pair does not contribute to single point mutations in DNA.

scholarly journals New homozygous gpt delta transgenic rat strain improves an efficiency of the in vivo mutagenicity assay

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Kenichi Masumura ◽  
Tomoko Ando ◽  
Akiko Ukai ◽  
Sho Fujiwara ◽  
Shigeo Yokose ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Gene Mutation ◽  
Point Mutations ◽  
Chromosome 1 ◽  
Transgenic Rat ◽  
Target Tissue ◽  
Sequencing Analysis ◽  
Rat Strain ◽  
Packaging Efficiency

Abstract Background Gene mutation assays in transgenic rodents are useful tools to investigate in vivo mutagenicity in a target tissue. Using a lambda EG10 transgene containing reporter genes, gpt delta transgenic mice and rats have been developed to detect point mutations and deletions. The transgene is integrated in the genome and can be rescued through an in vitro packaging reaction. However, the packaging efficiency is lower in gpt delta rats than in mice, because of the transgene in gpt delta rats being heterozygous and in low copy number. To improve the packaging efficiency, we herein describe a newly developed homozygous gpt delta rat strain. Results The new gpt delta rat has a Wistar Hannover background and has been successfully maintained as homozygous for the transgene. The packaging efficiency in the liver was 4 to 8 times higher than that of existing heterozygous F344 gpt delta rats. The frequency of gpt point mutations significantly increased in the liver and bone marrow of N-nitroso-N-ethylurea (ENU)- and benzo[a]pyrene (BaP)-treated rats. Spi− deletion frequencies significantly increased in the liver and bone marrow of BaP-treated rats but not in ENU-treated rats. Whole genome sequencing analysis identified ≥ 30 copies of lambda EG10 transgenes integrated in rat chromosome 1. Conclusions The new homozygous gpt delta rat strain showed a higher packaging efficiency, and could be useful for in vivo gene mutation assays in rats.

WHICH IS THE PROTON-SHUTTLE IN ISOXANTHOPTERIN DEAMINASE? QM/MM MD UNDERSTANDING

2013 ◽  
Vol 12 (08) ◽  
pp. 1341002 ◽  
Author(s):  
XIN ZHANG ◽  
MING LEI
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Glutamic Acid ◽  
Active Site ◽  
Nucleophilic Attack ◽  
Zinc Ions ◽  
Initial Model ◽  
Dynamics Simulations

The deamination process of isoxanthopterin catalyzed by isoxanthopterin deaminase was determined using the combined QM(PM3)/MM molecular dynamics simulations. In this paper, the updated PM3 parameters were employed for zinc ions and the initial model was built up based on the crystal structure. Proton transfer and following steps have been investigated in two paths: Asp336 and His285 serve as the proton shuttle, respectively. Our simulations showed that His285 is more effective than Aap336 in proton transfer for deamination of isoxanthopterin. As hydrogen bonds between the substrate and surrounding residues play a key role in nucleophilic attack, we suggested mutating Thr195 to glutamic acid, which could enhance the hydrogen bonds and help isoxanthopterin get close to the active site. The simulations which change the substrate to pterin 6-carboxylate also performed for comparison. Our results provide reference for understanding of the mechanism of deaminase and for enhancing the deamination rate of isoxanthopterin deaminase.

The Order of Phase Transition of Solvable DNA Melting Models

2003 ◽  
Vol 17 (16) ◽  
pp. 885-896 ◽  
Author(s):  
Su-Long Nyeo ◽  
I-Ching Yang
Keyword(s):  
Phase Transition ◽  
Hydrogen Bonds ◽  
Short Range ◽  
Scaling Laws ◽  
Dna Melting ◽  
Thermodynamic Quantities ◽  
Base Pairs ◽  
Order Of Phase Transition ◽  
Exactly Solvable ◽  
Dna Models

The phase transition of DNA molecules is studied in an exactly solvable formalism with the Morse and Deng–Fan potentials for the interstrand hydrogen bonds of nucleotide base pairs. It is shown that although the two potentials have different short-range behaviors, the thermodynamic quantities of the DNA system in these potentials enjoy the same scaling laws with the associated critical exponents, which are explicitly calculated. These exactly solvable DNA models are shown to exhibit a phase transition of the second order and the results of the analysis agree with previous studies.

Cooperative vibrational properties of hydrogen bonds in Watson–Crick DNA base pairs

2017 ◽  
Vol 41 (20) ◽  
pp. 12104-12109 ◽  
Author(s):  
Yulei Shi ◽  
Wanrun Jiang ◽  
Zhiyuan Zhang ◽  
Zhigang Wang
Keyword(s):  
Hydrogen Bonds ◽  
Vibrational Properties ◽  
Base Pairs ◽  
Dna Base ◽  
Dna Base Pairs

For the AT pair, Symst and Strech peaks further shift toward the red, giving the H-bonds an amplified effect (orange arrows).

Sign in / Sign up

Export Citation Format

Share Document