The drift-diffusion (Poisson-Nernst-Planck) model is applied to the potassium channel in a biological membrane plus surrounding solution baths. Two-dimensional cylindrically symmetric simulations of the K channel in KCl solutions are presented which show significant boundary layers at the ends of the channel and display the spreading of charge into the bath regions. The computed current-voltage curve shows excellent agreement with experimental measurements. In addition, the response of the K channel to time-dependent applied voltages is investigated.
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http://dx.doi.org/10.1016/j.jtbi.2011.09.010 | DOI Listing |
Narra J
December 2024
Department of Internal Medicine, Faculty of Medicine, Universitas Sebelas Maret, Surakarta, Indonesia.
Liddle syndrome, a rare form of monogenic hypertension, poses significant diagnostic and therapeutic challenges due to its phenotypic variability and the need for genetic testing. The rarity of the condition, coupled with the limited availability of first-line treatments such as epithelial sodium channel (ENaC) blockers, makes this case report particularly urgent and novel, highlighting alternative management strategies in resource-limited settings. The aim of this case report was to present the diagnostic challenges, therapeutic strategies, and clinical outcomes of a patient with Liddle syndrome who did not have access to ENaC blockers, emphasizing the importance of early recognition and personalized treatment.
View Article and Find Full Text PDFMalar J
January 2025
Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Background: Emodepside is an anthelmintic used in veterinary medicine that is currently under investigation in human clinical trials for the treatment of soil-transmitted helminths and possibly Onchocerca volvulus. Emodepside targets the calcium-activated voltage-gated potassium slowpoke 1 (SLO-1) channels of presynaptic nerves of pharynx and body wall muscle cells of nematodes leading to paralysis, reduced locomotion and egg laying, starvation, and death. Emodepside also has activity against Drosophila melanogaster SLO-1 channels.
View Article and Find Full Text PDFNat Chem Biol
January 2025
Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.
Voltage-gated ion channels (VGICs) are crucial targets for neuropsychiatric therapeutics owing to their role in controlling neuronal excitability and the established link between their dysfunction and neurological diseases, highlighting the importance of identifying modulators with distinct mechanisms. Here we report two small-molecule modulators with the same chemical scaffold, Ebio2 and Ebio3, targeting a potassium channel KCNQ2, with opposite effects: Ebio2 acts as a potent activator, whereas Ebio3 serves as a potent and selective inhibitor. Guided by cryogenic electron microscopy, patch-clamp recordings and molecular dynamics simulations, we reveal that Ebio3 attaches to the outside of the inner gate, employing a unique non-blocking inhibitory mechanism that directly squeezes the S6 pore helix to inactivate the KCNQ2 channel.
View Article and Find Full Text PDFBr J Pharmacol
January 2025
Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Background And Purpose: The antiepileptic drug ethosuximide (ETX) suppresses epileptiform activity in a mouse model of GNB1 syndrome, caused by mutations in Gβ protein, likely through the inhibition of G-protein gated K (GIRK) channels. Here, we investigated the mechanism of ETX inhibition (block) of different GIRKs.
Experimental Approach: We studied ETX inhibition of GIRK channels expressed in Xenopus oocytes with or without their physiological activator, the G protein subunit dimer Gβγ.
Neurochem Int
January 2025
Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, PR China. Electronic address:
Microglia-mediated neuroinflammation plays a critical role in neuronal damage in neurodegenerative disorders such as Alzheimer's disease. Evidence shows that voltage-gated potassium (Kv) channels regulate microglial activation. We previously reported that copper dyshomeostasis causes neuronal injury via activating microglia.
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