Changes of electrostatic potential around the DNA molecule resulting from chemical modifications of nucleotides may play a role in enzymatic recognition of damaged sites. Effects of chemical modifications of nucleotides on the structure of DNA have been characterized through electronic structure computations. Quantum mechanical structural optimizations of fragments of five pairs of nucleotides with thymine or thymine glycol were performed at the density functional level of theory with a B3LYP exchange-correlation functional and 6-31G(d,p) basis sets. The electrostatic potential (EP) around DNA fragments was projected on a cylindrical surface around the double helix. The 2D maps of EP of intact and damaged DNA fragments were compared using image analysis methods to identify and measure modifications of the EP that result from the occurrence of thymine glycol. It was found that distortions of phosphate groups and displacements of the accompanying countercations by up to approximately 0.5 angstroms along the axis of DNA are clearly reflected in the EP maps. Modifications of the EP in the major groove of DNA near the damaged site are also reported.
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Turk J Chem
November 2024
Division of Organic Chemistry, Department of Chemistry, Faculty of Engineering, İstanbul University-Cerrahpaşa, İstanbul, Turkiye.
The detection of intracellular biothiols (cysteine, N-acetyl cysteine, and glutathione) with high selectivity and sensitivity is important to reveal biological functions. In this study, a 2-(2-methoxy-4-methylphenoxy)-3-chloro-5,8-dihydroxynaphthalene-1,4-dione (DDN-O) compound was newly synthesized and used as a fluorogenic probe (detector molecule) in the fluorometric method for the rapid, highly selective, and sensitive determination of biothiols. The intensity values (λ = 260 nm, λ = 620 nm) of the product were measured by adding biothiols to the reaction medium at varying concentrations and the glutathione equivalent thiol content values of each biothiol were calculated.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, People's Republic of China.
Efficient capture of single-stranded DNA (ssDNA) is crucial for high-throughput sequencing, which influences the speed and accuracy of genetic analysis. Electrophoresis (EP) and electro-osmotic flow (EOF) have a significant impact on the translocation behavior of ssDNA through the nanopore. Experimentally, dynamically tracking these two effects remains challenging, and conventional numerical methods also struggle to capture their dynamic properties in the presence of DNA.
View Article and Find Full Text PDFJ Chem Inf Model
January 2025
Computer-Aided Drug Discovery, Global Discovery Chemistry, Novartis Biomedical Research, 181 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
Targeted covalent inhibition is a powerful therapeutic modality in the drug discoverer's toolbox. Recent advances in covalent drug discovery, in particular, targeting cysteines, have led to significant breakthroughs for traditionally challenging targets such as mutant KRAS, which is implicated in diverse human cancers. However, identifying cysteines for targeted covalent inhibition is a difficult task, as experimental and in silico tools have shown limited accuracy.
View Article and Find Full Text PDFNat Commun
January 2025
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
Micro actuators are widely used in NEMS/MEMS for control and sensing. However, most are designed with suspended beams anchored at fixed points, causing two main issues: restricted actuated stroke and movement modes, and reduced lifespan due to fatigue from repeated beam deformation, contact wear and stiction. Here, we develop an electrostatic in-plane actuator leveraging structural superlubric sliding interfaces, characterized by zero wear, ultralow friction, and no fixed anchor.
View Article and Find Full Text PDFFood Res Int
January 2025
College of Life Sciences, Northeast Forestry University, Harbin 150040, PR China; Key Laboratory of Forest Food Resources Utilization of Heilongjiang Province, Harbin 150040, PR China. Electronic address:
In this study, we developed a double-layer colon-targeted microcapsule. It used the Maillard product of gelatin-isomaltooligosaccharide (GI180) and zein-shellac complex (ZS) as bio-based materials, plant extracts (MPL) and Lactobacillus plantarum JJBYG12 (JJBYG12) were co-encapsulated, endowing them with strong resistance to harsh environments and precise intestinal adhesion and targeting ability. The research results indicated that ZS11 exhibits hydrogen bonding and electrostatic interactions.
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