The folding energy landscape of RNA is greatly affected by interactions between the RNA and counterions that neutralize the backbone negative charges and may also participate in tertiary contacts. Valence, size, coordination number, and electron shell structure can all contribute to the energetic stabilization of specific RNA conformations. Using single-molecule fluorescence resonance energy transfer (smFRET), we have examined the folding properties of the RNA transcript of human mitochondrial tRNA(Lys), which possesses two different folded states in addition to the unfolded one under conditions of thermodynamic equilibrium. We have quantitatively analyzed the degree of RNA tertiary structure stabilization for different types of cations based on a thermodynamic model that accounts for multiple conformational states and RNA-ion interactions within each state. We have observed that small monovalent ions stabilize the tRNA tertiary structure more efficiently than larger ones. More ions were found in close vicinity of compact RNA structures, independent of the type of ion. The largest conformation-dependent binding specificity of ions of the same charge was found for divalent ions, for which the ionic radii and coordination properties were responsible for shaping the folding free energy.
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http://dx.doi.org/10.1021/bi101804t | DOI Listing |
J Phys Chem B
January 2025
School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
Hydration free energy (HFE) of molecules is a fundamental property having importance throughout chemistry and biology. Calculation of the HFE can be challenging and expensive with classical molecular dynamics simulation-based approaches. Machine learning (ML) models are increasingly being used to predict HFE.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
The near-infrared electrochemiluminescence (NIR-ECL) technique has received special attention in cell imaging and biomedical analysis due to its deep tissue penetration, low background interference, and high sensitivity. Although cyanine-based dyes are promising NIR-ECL luminophores, limited ECL efficiency and the need for exogenous coreactants have prevented their widespread application. In this work, poly[9,9-bis(3'-(-dimethylamino)propyl)-2,7-fluorene]--2,7-(9,9-dioctylfluorene)] (PFN) was innovatively developed to significantly invigorate the NIR-ECL performance of heptamethine cyanine dye IR 783 by the resonance energy transfer (RET) strategy.
View Article and Find Full Text PDFHumans excel at applying learned behavior to unlearned situations. A crucial component of this generalization behavior is our ability to compose/decompose a whole into reusable parts, an attribute known as compositionality. One of the fundamental questions in robotics concerns this characteristic: How can linguistic compositionality be developed concomitantly with sensorimotor skills through associative learning, particularly when individuals only learn partial linguistic compositions and their corresponding sensorimotor patterns? To address this question, we propose a brain-inspired neural network model that integrates vision, proprioception, and language into a framework of predictive coding and active inference on the basis of the free-energy principle.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Chemistry and Pharmacy, Institute of Physical Chemistry, University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany.
Mucins are the macromolecular key components of mucus. On wet epithelia of mammals, mucin solutions and gels act as powerful biolubricants and reduce friction and wear by generating a sacrificial layer and establishing hydration lubrication. Yet the structure-function relationship of mucin adhesion and lubrication remains elusive.
View Article and Find Full Text PDFNew Phytol
January 2025
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium.
Precise gene-editing methods are valuable tools to enhance genetic traits. Gene editing is commonly achieved via stable integration of a gene-editing cassette in the plant's genome. However, this technique is unfavorable for field applications, especially in vegetatively propagated plants, such as many commercial tree species, where the gene-editing cassette cannot be segregated away without breaking the genetic constitution of the elite variety.
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