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Artificial molecular photoswitches that can be reversibly controlled into different configurations by external light stimulation have broad application prospects in various fields, such as materials and chemical biology. Among them, the pyrrole hemithioindigo (PHT) photoswitch has a geometric structure similar to that of the fluorescent protein chromophore. What happens when the chromophore is replaced by PHT, and does it achieve similar functions to the original one? To answer these questions, we carried out ONIOM(QM/MM) and classical molecular dynamics studies on the photoisomerization mechanism and spectroscopic properties of PHT in the fluorescent protein. The results showed that in the protein environment, the fate of excited PHT is governed by the competition between fluorescence emission and hula-twist isomerization. Due to the strong steric hindrance effects caused by the interlacing residues in the protein that restrict the PHT conformation transformation, the cis-to-trans isomerization process of PHT needs to overcome a barrier of at least 4.9 kcal/mol; thus, fluorescence emission is more dominant in competition. It is also found that the intermolecular interaction between LYS67 and the carbonyl oxygen of PHT has a significant effect on the fluorescence emission. These results revealed the photochemical reaction mechanism of a light-driven molecular switch in the fluorescent protein and provided further theoretical support for the field of chemical biology.
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http://dx.doi.org/10.1021/acs.jpcb.3c05894 | DOI Listing |
J Bacteriol
September 2025
Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
Essential genes are interesting in their own right and as potential antibiotic targets. To date, only one report has identified essential genes on a genome-wide scale in , a problematic pathogen for which treatment options are limited. That foundational study used large-scale transposon mutagenesis to identify 404 protein-encoding genes as likely to be essential for vegetative growth of the epidemic strain R20291.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
September 2025
Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.
Purpose: Adeno-associated viruses (AAVs) have become the preferred vector for gene therapy in ophthalmology. However, requirements for specific cell surface receptors limit AAV-mediated retinal cell transduction efficiency. This led to the need to engineer novel AAV vectors for widespread retinal transduction and transgene expression.
View Article and Find Full Text PDFBrain
September 2025
Okinawa Institute of Science and Technology Graduate University, Okinawa, 904-0495, Japan.
Animal models of the pathology of Parkinson's disease (PD) have provided most of the treatments to date, but the disease is restricted to human patients. In vitro models using human pluripotent stem cells (hPSCs)-derived neural organoids have provided improved access to study PD etiology. This study established a method to generate human striatal-midbrain assembloids (hSMAs) from hPSCs for modeling alpha-synuclein (α-syn) propagation and recapitulating basal ganglia circuits, including nigrostriatal and striatonigral pathways.
View Article and Find Full Text PDFNeuropathol Appl Neurobiol
October 2025
Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, Târgu Mureș, Romania.
Aims: The clusterin (CLU) gene is genetically associated with Alzheimer's disease (AD), and CLU levels have been shown to positively correlate with regional Aβ deposition in the brain, including in arteries from cerebral amyloid angiopathy (CAA) patients. CLU has also been shown to alter the aggregation, toxicity and blood-brain barrier transport of amyloid beta (Aβ) and has therefore been suggested to play a key role in regulating the balance between Aβ deposition and clearance in both the brain and cerebral blood vessels. However, it remains unclear whether the role of clusterin in relation to Aβ deposition is protective or pathogenic.
View Article and Find Full Text PDFFood Sci Biotechnol
October 2025
Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, 11433 Riyadh, Saudi Arabia.
This research study investigates the relationship between the structural characteristics, water solubility, and protein digestibility of quinoa proteins (QPs) during fermentation. The fermentation process induces structural modifications in QPs, thereby enhancing their surface properties and functional attributes. Using advanced analytical techniques, such as ultraviolet, fluorescence, and FT-IR spectra, it has been demonstrated that fermented QPs exhibit significant structural changes (P < 0.
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