We have explored the permeation and blockage of ions in sodium channels, relating the channel structure to function using electrostatic profiles and Brownian dynamics simulations. The model used resembles the KcsA potassium channel with an added external vestibule and a shorter selectivity filter. The electrostatic energy landscape seen by permeating ions is determined by solving Poisson's equation. The two charged amino acid rings of Glu-Glu-Asp-Asp (EEDD) and Asp-Glu-Lys-Ala (DEKA) around the selectivity filter region are seen to play a crucial role in making the channel sodium selective, and strongly binding calcium ions such that they block the channel. Our model closely reproduces a range of experimental data including the current-voltage curves, current-concentration curves and blockage of monovalent ions by divalent ions.
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http://dx.doi.org/10.1016/j.bbamem.2004.11.011 | DOI Listing |
Metasurfaces offer a powerful tool to realize label-free and highly sensitive Raman spectroscopy. Embedding metasurfaces into microfluidic channels is promising to establish a new characterizing platform for microfluids. In this Letter, we present a highly stable method for improving the Raman scattering intensity of biological microfluids by using a microfluidic chip embedded with a plasmonic metasurface.
View Article and Find Full Text PDFArch Med Res
January 2025
Programa de Investigación de Cancer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico; Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico. Electronic address:
Na⁺/H⁺ exchanger regulatory factor 2 (NHERF2) is a nucleocytoplasmic protein initially identified as a regulator of membrane-bound sodium-hydrogen exchanger 3 (NHE3). In the cytoplasm, NHERF2 regulates the activity of G protein-coupled receptors (GPCRs), including beta-2 adrenergic receptor (2β-AR), lysophosphatidic acid receptor 2, and parathyroid hormone type 1 receptor. In the nucleus, NHERF2 acts as a coregulator of transcription factors such as sex-determining region Y protein (SRY), involved in male sex determination, and estrogen receptor alpha (ERα).
View Article and Find Full Text PDFNano Lett
January 2025
Advanced Energy Storage Technology and Equipment Research Institute, Ningbo University, Ningbo, Zhejiang 315211, China.
Plateau-dominated hard carbon with a high rate of performance is challenging to obtain, and the in-depth mechanism of pore structure on the diffusion of sodium ions remains unclear. In this study, a facile liquid-phase molecular reconstruction strategy is proposed to regulate the orientation of the β-cyclodextrin molecules and prepare spherical hard carbon with continuous and ordered pore channels. Through detailed characterization, this approach is confirmed to optimize the accumulation of Na in the dispersion region, thus improving the plateau kinetics and enhancing the utilization of closed pores.
View Article and Find Full Text PDFChem Sci
January 2025
Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education and Faculty of Chemistry, Northeast Normal University 5268 Renmin Street Changchun 130024 P. R. China
Two-dimensional conductive metal-organic frameworks (2D c-MOFs) with high electrical conductivity and tunable structures hold significant promise for applications in metal-ion batteries. However, the construction of 3D interpenetrated c-MOFs for applications in metal-ion batteries is rarely reported. Herein, a 3D four-fold interpenetrated c-MOF (Cu-DBC) constructed by conjugated and contorted dibenzo[,]chrysene-2,3,6,7,10,11,14,15-octaol (DBC) ligands is explored as an advanced cathode material for sodium-ion batteries (SIBs) for the first time.
View Article and Find Full Text PDFDrug Des Devel Ther
January 2025
State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China.
Purpose: The major cardiac voltage-gated sodium channel Na1.5 (I) is essential for cardiac action potential initiation and subsequent propagation. Compound Chinese medicine Wenxin Keli (WXKL) has been shown to suppress arrhythmias and heart failure.
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