We have perturbed myosin nucleotide binding site with magnesium-, manganese-, or calcium-nucleotide complexes, using metal cation as a probe to examine the pathways of myosin ATPase in the presence of actin. We have used transient time-resolved FRET, myosin intrinsic fluorescence, fluorescence of pyrene labeled actin, combined with the steady state myosin ATPase activity measurements of previously characterized D.discoideum myosin construct A639C:K498C. We found that actin activation of myosin ATPase does not depend on metal cation, regardless of the cation-specific kinetics of nucleotide binding and dissociation. The rate limiting step of myosin ATPase depends on the metal cation. The rate of the recovery stroke and the reverse recovery stroke is directly proportional to the ionic radius of the cation. The rate of nucleotide release from myosin and actomyosin, and ATP binding to actomyosin depends on the cation coordination number.
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http://dx.doi.org/10.1002/pro.2376 | DOI Listing |
Chem Sci
January 2025
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences Shanghai 201203 China
α-Halo borides are generally constructed Matteson homologation, and the synthesis of both fluorinated and functionalized ambiphilic boronates is challenging and has received inadequate attention. Herein, we describe the -methyliminodiacetyl boronate [B(MIDA)]-directed halogenation of alkenes a complementary sequence involving fluoroalkyl radical addition followed by guided radical-to-metal oxidative addition and C-X reductive elimination. The alkali cation and functional groups in B(MIDA) enable coulombic interaction and weak attraction with halogens, which could weaken the Pd-X bond and assist in C-X bond formation and is verified by DFT calculations.
View Article and Find Full Text PDFInorg Chem
January 2025
Key Laboratory of Applied Surface and Colloid Chemistry (MOE), School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi 710062, China.
Fluorescent metal-organic frameworks (MOFs) are promising sensing materials that have received much attention in recent years, in which the organic ligand conformation changes usually lead to variations of their sensing behavior. Based on this, in the present work, perylene diimide (PDI) derivatives with excellent photochemical properties closely related to their conformation and molecule packing fashion were selected as organic linkers to detect sarin simulant diethyl chlorophosphate (DCP). By the coordination interactions with large lanthanide cations through terminal carboxylate groups from the PDI derivative, a series of one-dimensional coordination polymers, named [Ln(PDICl-2COO)(μ-O)(DMF)] (SNNU-112, Ln = Yb/Tb/Sm/Nd/Pr/Gd/Eu/Er/Ce, PDICl-2COOH = ,'-bis(4-benzoic acid)-1,2,6,7-tetrachlorohydrazone-3,4,9,10-tetracarboxylic acid diimide) were synthesized.
View Article and Find Full Text PDFInorg Chem
January 2025
MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China.
A novel antimonotungstate (AT)-based heterometallic framework {[Er(HO)][Fe(Hpdc)(B-β-SbWO)]}·50HO (, Hpdc = pyridine-2,5-dicarboxylic acid) was obtained through a synergistic strategy of in situ-generated transition-metal-encapsulated polyoxometalate (POM) building units and the substitution reaction. Its structural unit is composed of a tetra-Fe-substituted Krebs-type [Fe(Hpdc)(B-β-SbWO)] subunit and two [Er(HO)] cations. This subunit can be regarded as a product of carboxylic oxygen atoms of Hpdc ligands replacing active water ligands in the [Fe(HO)(B-β-SbWO)] species.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Cardiovascular Health Across the Life Span, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
Preserving the balance of metabolic processes in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), is crucial for optimal vascular function and integrity. ECs are metabolically active and depend on aerobic glycolysis to efficiently produce energy for their essential functions, which include regulating vascular tone. Impaired EC metabolism is linked to endothelial damage, increased permeability and inflammation.
View Article and Find Full Text PDFSci Rep
January 2025
Geology Department, Faculty of Science, Assiut University, Assiut, Egypt.
Limestone mining waste and its derived CaO were checked as an adsorbents of pb, Cu, and Cd ions from water solution. The characterization of Limestone and calcined limestone was studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), and Surface area measurements (BET). The optimum conditions of sorbent dosage, pH, initial concentration, and contact time factors were investigated for pristine limestone and calcined limestone absorbents.
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