The mutation rate of mitochondrial DNA (mtDNA) is 17 times higher than nuclear DNA, and these mutations can cause mitochondrial disease in 1 of 10.000 people. The T10609C mutation was identified in type 2 diabetes mellitus (T2DM) patients and the C10676G mutation in cataract patients, with both mutations occurring in the ND4L gene of mtDNA that encodes ND4L protein. ND4L protein, a subunit of complex I in the respiratory complex, has been shown to play a role in the proton translocation process. The purpose of this study was to investigate the effect of both mutations on the proton translocation mechanism. Mutation mapping showed changes in amino acids M47T (T10609C) and C69W (C10676G). The 100 ns molecular dynamics (MD) simulations performed on native and mutants of ND4L-ND6 subunits. It is revealed that the native model had a similar proton translocation pathway to that of complex I from other organisms. Interestingly, the mutant M47T and C69W showed the interruption of the translocation pathway by a hydrogen bond formation between Glu34 and Tyr157. It is observed that the mutations were restricting the passage of water molecules through the transmembrane region. These results could help to develop the computational assay for the validation of a specific genetic biomarker for T2DM and cataracts.
Mitochondrial DNA mutations, such as A3243G, can affect changes in the structure of biomolecules, resulting in changes in the structure of Leucine transfer Ribose Nucleic Acid to form a dimer. Dimer structure modeling is needed to determine the properties of the structure. However, the lack of a structure template for the transfer of Ribose Nucleic Acid (tRNA) is challenging for the modeling of mutant structures of tRNA, especially mitochondrial tRNA that are susceptible to mutation. Therefore, this study predicted the structure of mitochondrial leucine tRNA and its stability through a knowledge-based method and molecular dynamics. Structural modeling and initial assessment were performed using RNAComposer and MolProbity, HNADOCK, and Discovery studios to form the dimer structure. Molecular dynamics simulations for stability analysis were performed using Amber and AmberTools20 software, showing that the conformational energy of the mutant leucine tRNA dimer structure was lower than the native structure. Moreover, the Root Mean Square Deviation (RMSD) of monomer native leucine tRNA was lower than the mutant, indicating that the dimer structure of mutant leucine tRNA is more stable than usual, and the normal leucine tRNA is more stable than the mutant.
Typhonium flagelliforme is an Indonesian herbal plant used and applied traditionally to treat cancer diseases. Gamma rays have irradiated rodent tuber mutant plant at six doses gray to in-crease the chemical compounds of anticancer activity. The effect of isolated compounds from ro-dent tuber mutant plants has never been studied and published yet. Our study unveiled the poten-tial of stigmasterol as a remarkable cytotoxic agent and the significant contribution of NMR spectroscopy, IR, Mass spectra, QTOF MS towards the isolation and identification of this anti-cancer agent. Stigmasterol was isolated from T. flagelliforme mutant plant. Stigmasterol was more effective against MCF-7 cells with an IC50 value of 0.1623 µM than Cisplatin with IC50 value 13.2 µM. It is the most potential and active fraction in the human breast cancer cell line. The mo-lecular docking study analyzed the chemical profile of stigmasterol to confirm the receptor in agonist binding sites. The prediction of the toxicity of stigmasterol compounds using in silico and analysis of its interaction with the receptor can act as a competitive regulator with a high-affinity binding site on FXR. Stigmasterol has potential as a candidate for an anticancer drug that pro-moting further clinical action.
Studies on the interaction between gold nanoparticles
(AuNPs) and
functional proteins have been useful in developing diagnostic and
therapeutic agents. Such studies require a realistic computational
model of AuNPs for successful molecular design works. This study offers
a new multilayer model of AuNPs to address the inconsistency between
its molecular mechanics’ interpretation and AuNP’s plasmonic
nature. We performed partial charge quantum calculation of AuNPs using
Au13 and Au55 models. The result showed that
it has partial negative charges on the surface and partial positive
charges on the inner part, indicating that the AuNP model should be
composed of multiatom types. We tested the partial charge parameters
of these gold (Au) atoms in classical molecular dynamics simulation
(CMD) of AuNPs. The result showed that our parameters performed better
in simulating the adsorption of Na+ and dicarboxy acetone
in terms of consistency with surface charge density than the zero
charges Au in the interface force field (IFF). We proposed that the
multiple-charged AuNP model can be developed further into a simpler
four-atom type of Au in a larger AuNP size.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.