The bioluminescence reaction in dinoflagellates involves the oxidation of an open-chain tetrapyrrole by the enzyme dinoflagellate luciferase (LCF). The activity of LCF is tightly regulated by pH, where the enzyme is essentially inactive at pH ∼8 and optimally active at pH ∼6. Little is known about the mechanism of LCF or the structure of the active form of the enzyme, although it has been proposed that several intramolecularly conserved histidine residues in the N-terminal region are important for the pH regulation mechanism. Here, constant pH accelerated molecular dynamics was employed to gain insight into the conformational activation of LCF induced by acidification.
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http://dx.doi.org/10.1021/acs.biochem.7b00873 | DOI Listing |
BMC Bioinformatics
January 2025
International Institute "Solution Chemistry of Advanced Materials and Technologies", ITMO University, Saint-Petersburg, Russian Federation, 191002.
Background: Deoxyribozymes or DNAzymes represent artificial short DNA sequences bearing many catalytic properties. In particular, DNAzymes able to cleave RNA sequences have a huge potential in gene therapy and sequence-specific analytic detection of disease markers. This activity is provided by catalytic cores able to perform site-specific hydrolysis of the phosphodiester bond of an RNA substrate.
View Article and Find Full Text PDFEnviron Technol
January 2025
Solid-State Physics and Accelerators Department, National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
Waste polyethylene (WPE) and virgin polyethylene (VPE) (50:50) thermoplastic have been melt-mixed with biochar (BC) made from orange peels at ratios of 5, 10, and 15(Phr) to evaluate how the filler content affected the mechanical, thermal, optical, electrical conductivity, and electromagnetic interference (EMI). γ-rays was applied to the prepared specimens to assess how radiation affected the created biocomposites. From the obtained results, the combination of BC with γ-rays, at doses of up to 100 kGy, with thermoplastic resulted in an enhanced mechanical property, particularly for composites containing 15 Phr of BC added because of its unique structure and excellent dispersion.
View Article and Find Full Text PDFChem Sci
December 2024
State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology Beijing 100029 China
The shelf life of 2D MXenes in functional devices and colloidal dispersions is compromised due to oxidation in the aqueous system. Herein, a systematic investigation was carried out to explore the potential of various amino compounds as antioxidants for TiCT MXenes. A range of basic, acidic, and neutral amino acids were examined for their effectiveness, where certain antioxidants failed to protect MXenes from oxidation, while others accelerated their decomposition.
View Article and Find Full Text PDFPhys Med Biol
January 2025
Department of Accelerator and Medical Physics, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, JAPAN.
The tumor microenvironment characterized by heterogeneously organized vasculatures causes intra-tumoral heterogeneity of oxygen partial pressure at the cellular level, which cannot be measured by current imaging techniques. The intra-tumoral cellular heterogeneity may lead to a reduction of therapeutic effects of radiation. The purpose of this study was to investigate the effects of the heterogeneity on biological effectiveness of H-, He-, C-, O-, and Ne-ion beams for different oxygenation levels, prescribed dose levels, and cell types.
View Article and Find Full Text PDFJ Vis
January 2025
Institut de Neurosciences de la Timone, CNRS & Aix-Marseille Université, Marseille, France.
Sensory-motor systems can extract statistical regularities in dynamic uncertain environments, enabling quicker responses and anticipatory behavior for expected events. Anticipatory smooth pursuit eye movements (aSP) have been observed in primates when the temporal and kinematic properties of a forthcoming visual moving target are fully or partially predictable. To investigate the nature of the internal model of target kinematics underlying aSP, we tested the effect of varying the target kinematics and its predictability.
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