Single nucleic acid molecules form hairpins that may stabilize secondary and tertiary structures as well as perform enzymatic and other chemical functions. Considerable progress has been made in the effort to understand the contributions of various factors to the stability of a given hairpin sequence. For a given sequence, it is possible to compute both the most likely structural arrangements and their associated free energies over a range of experimental conditions. However, there are many observed hairpin irregularities for which the energies and function are not well understood. Here we examine the irregular RNA Transactivation Response (TAR) hairpin from the HIV-1 genome. Using single molecule optical tweezers, the hairpin is force unfolded, revealing the overall unfolding free energy and the character of the transition state. These measurements allow the construction of a simple energy landscape from unfolding measurements, which can be directly compared to a theoretical landscape. This method is easily adapted to other structures, including the effects of noncanonical bases and even ligand binding.
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http://dx.doi.org/10.1007/978-1-4939-8582-1_21 | DOI Listing |
Parasit Vectors
January 2025
Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC, 3010, Australia.
Background: Nippostrongylus brasiliensis-a nematode of rodents-is commonly used as a model to study the immunobiology of parasitic nematodes. It is a member of the Strongylida-a large order of socioeconomically important parasitic nematodes of animals. Lipids are known to play essential roles in nematode biology, influencing cellular membranes, energy storage and/or signalling.
View Article and Find Full Text PDFNat Commun
January 2025
School of Environmental and Chemical Engineering, Wuyi University, Jiangmen, PR China.
Developing efficient strategies for the deoxygenative functionalization of carbonyl compounds is crucial for enhancing the effective utilization of biomass and the upgrading of chemical feedstocks. In this study, we present an elegant cathodic reduction strategy that enables a tandem alkylation/dearomatization reaction between quinoline derivatives and aryl aldehydes/ketones in a one-pot process. Our approach can be executed via two distinct paths: the aluminum (Al)-facilitated spin-center shift (SCS) path and the Al-facilitated direct deoxygenation path.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
February 2025
Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA; The Framingham Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
Background: Ultra-processed food consumption is emerging as a risk factor for various cardiometabolic diseases, however its association with dementia and Alzheimer's disease has rarely been explored.
Objectives: We sought to examine whether ultra-processed food consumption is associated with risk of all-cause dementia and Alzheimer's disease among middle-age and older adults.
Design: A prospective cohort study.
Anal Chim Acta
February 2025
Food Inspection and Quarantine Technology Center of Shenzhen Customs, Shenzhen Academy of Inspection and Quarantine, Shenzhen, 518045, PR China.
Background: Ochratoxin A (OTA) is toxic secondary metabolites produced by fungi and can pose a serious threat to food safety and human health. Due to the high stability and toxicity, OTA contamination in agricultural products is of great concern. Therefore, the development of a highly sensitive and reliable OTA detection method is crucial to ensure food safety.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Engineering Research Center for Hemp and Product in Cold Region of Ministry of Education, School of Light Industry and Textile, Qiqihar University, Qiqihar 161006, PR China. Electronic address:
From the perspective of sustainable development and practical applications, there is a significant demand for the design of advanced cellulose-based film materials with superior mechanical, optical, and functional properties utilizing environmentally friendly strategies. Herein, biodegradable, mechanically robust and flame-retardant cellulose films with adjustable optical performance were successfully fabricated by in situ synthesis of NH-UiO(Zr)-66 via a DMF-free green process at room temperature. The results indicate that the introduction of NH-UiO(Zr)-66 enables films to realize a desirable flame retardancy (the limiting oxygen index (LOI) increased significantly from 19.
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