Calcium channel family members activate at different membrane potentials, which enables tissue specific calcium entry. Pore mutations affecting this voltage dependence are associated with channelopathies. In this review we analyze the link between voltage sensitivity and corresponding kinetic phenotypes of calcium channel activation. Systematic changes in hydrophobicity in the lower third of S6 segments gradually shift the activation curve thereby determining the voltage sensitivity. Homology modeling suggests that hydrophobic residues that are located in all four S6 segments close to the inner channel mouth might form adhesion points stabilizing the closed gate. Simulation studies support a scenario where voltage sensors and the pore are essentially independent structural units. We speculate that evolution designed the voltage sensing machinery as robust "all-or-non" device while the varietys of voltage sensitivities of different channel types was accomplished by shaping pore stability.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3196840 | PMC |
http://dx.doi.org/10.4161/chan.2.2.5999 | DOI Listing |
Front Pharmacol
January 2025
IDiBE-Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, Elche, Spain.
The Selectivity Filter (SF) in tetrameric K channels, has a highly conserved sequence, TVGYG, at the extracellular entry to the channel pore region. There, the backbone carbonyl oxygens from the SF residues, create a stack of K binding sites where dehydrated K binds to induce a conductive conformation of the SF. This increases intersubunit interactions and confers a higher stability to the channel against thermal denaturation.
View Article and Find Full Text PDFPeerJ
January 2025
Plant Production Department, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia.
Wheat, a staple food crop globally, faces the challenges of limited water resources and sustainable soil management practices. The pivotal elements of the current study include the integration of activated acacia biochar (AAB) in wheat cultivation under varying irrigation regimes (IR). A field trial was conducted in the Botanical Garden, University of the Punjab, Lahore during 2023-2024, designed as a split-split-plot arrangement with RCBD comprising three AAB levels (0T, 5T, and 10T, T = tons per hectare) three wheat cultivars (Dilkash-2020, Akbar-2019, and FSD-08) receiving five IR levels (100%, 80%, 70%, 60%, and 50% field capacity).
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Chemistry Department, Faculty of Science, Damanhour University, Damanhour, Egypt.
In the current work, three adsorbent materials were developed: biochar derived from date palm fiber (C), date palm fiber biochar/chitosan nanoparticles (CCS), and biochar/chitosan nanoparticle composite supplemented with glutamine (CCSG). These compounds were used as solid adsorbents to remove As from polluted water. Several characterization approaches were used to investigate all the synthesized solid adsorbents, including thermogravimetric analysis, N adsorption/desorption isotherm, scanning electron microscopy, transmission electron microscopy (TEM), attenuated total reflectance with Fourier transform infrared, and zeta potential.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Leibniz University Hanover: Leibniz Universitat Hannover, Institute for Solid State Physics, GERMANY.
Graphdiyne (GDY) has been considered a promising electrode material for application in electrochemical energy storage. However, studies on GDY featuring an ordered interlayer stacking are lacking, which is supposed to be another effective way to increase lithium binding sites and diffusion pathways. Herein, we synthesized a hydrogen-substituted GDY (HsGDY) with a highly-ordered AA-stacking structure via a facile alcohol-thermal method.
View Article and Find Full Text PDFACS Environ Au
January 2025
Department of Chemical and Biomolecular Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea.
Graphene-based materials can be potentially utilized for separation membranes due to their unique structural properties such as precise molecular sieving by interlayer spacing or pore structure and excellent stability in harsh environmental conditions. Therefore, graphene-based membranes have been extensively demonstrated for various water treatment applications, including desalination, water extraction, and rare metal ion recovery. While most of the utilization has still been limited to the laboratory scale, emerging studies have dealt with scalable approaches to show commercial feasibility.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!