The steroidal neurotoxin (-)-batrachotoxin functions as a potent agonist of voltage-gated sodium ion channels (Nas). Here we report concise asymmetric syntheses of the natural (-) and non-natural (+) antipodes of batrachotoxin, as well both enantiomers of a C-20 benzoate-modified derivative. Electrophysiological characterization of these molecules against Na subtypes establishes the non-natural toxin enantiomer as a reversible antagonist of channel function, markedly different in activity from (-)-batrachotoxin. Protein mutagenesis experiments implicate a shared binding side for the enantiomers in the inner pore cavity of Na These findings motivate and enable subsequent studies aimed at revealing how small molecules that target the channel inner pore modulate Na dynamics.
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http://dx.doi.org/10.1126/science.aag2981 | DOI Listing |
Biophys Chem
January 2025
La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia. Electronic address:
The rapid spread of antibiotic-resistant strains of bacteria has created an urgent need for new alternative antibiotic agents. Membrane disrupting antimicrobial peptides (AMPs): short amino acid sequences with bactericidal and fungicidal activity that kill pathogens by permeabilizing their plasma membrane may offer a solution for this global health crisis. Magainin 2 is an AMP secreted by the African clawed frog (Xenopus laevis) that is described as a toroidal pore former membrane disrupting AMP.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Material Science and Engineering, University of Jinan, Jinan 250022, PR China. Electronic address:
Some biomasses like cotton contain natural fibrous structures. This is a desirable structural feature for exposure of adsorption sites on cotton-derived activated carbon (AC). This was verified herein by conducting activation of cotton with ZnCl, HPO, KCO or KOH, probing whether structural transformation during activation could be confined inside a cotton fiber.
View Article and Find Full Text PDFSci Rep
January 2025
School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang, 421002, China.
The extraction of coal seams with high gas content and low permeability presents significant challenges, particularly due to the extended period required for gas extraction to meet safety standards and the inherently low extraction efficiency. Hydraulic fracturing technology, widely employed in the permeability enhancement of soft and low-permeability coal seams, serves as a key intervention. This study focuses on the high-rank raw coal from the No.
View Article and Find Full Text PDFElife
January 2025
Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States.
Calcium and integrin-binding protein 2 (CIB2) and CIB3 bind to transmembrane channel-like 1 (TMC1) and TMC2, the pore-forming subunits of the inner-ear mechano-electrical transduction (MET) apparatus. These interactions have been proposed to be functionally relevant across mechanosensory organs and vertebrate species. Here, we show that both CIB2 and CIB3 can form heteromeric complexes with TMC1 and TMC2 and are integral for MET function in mouse cochlea and vestibular end organs as well as in zebrafish inner ear and lateral line.
View Article and Find Full Text PDFMolecules
December 2024
Shanxi Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China.
Lithium-sulfur (Li-S) batteries have emerged as a promising candidate for next-generation high-energy rechargeable lithium batteries, but their practical application is impeded by the sluggish redox kinetics and low sulfur loading. Here, we report the in situ growth of δ-MnO nanosheets onto hierarchical porous carbon microspheres (HPCs) to form an HPCs/S@MnO composite for advanced lithium-sulfur batteries. The delicately designed hybrid architecture can effectively confine LiPSs and obtain high sulfur loading up to 10 mg cm, in which the inner carbon microspheres with a large pore volume and large specific surface area can encapsulate high sulfur content, and the outer MnO nanosheets, as a catalytic layer, can improve the conversion reaction of LiPSs and suppress the shuttle effect.
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