The structure of a 39 amino acid proteolytic fragment of rabbit skeletal troponin C containing the fourth Ca(2+)-binding site has been determined by an approach involving nuclear magnetic resonance (NMR) spectroscopy combined with hybrid distance geometry-dynamical simulated annealing calculations. Hydrodynamic and NMR evidence establishes unambiguously that the fragment forms a stable dimer in solution in the presence of excess Ca2+. The calculation of the dimeric structure is based on a total of 1056 experimental restraints comprising 422 interproton distances, 35 phi, 28 psi, and 28 chi 1 torsion angle restraints within each subunit, 30 intermonomer distance restraints, and 6 Ca2+ restraints per subunit. A total of 48 final structures were calculated having an rms deviation about the mean atomic backbone coordinate positions of 1.0 A for residues Asp128-Glu156. The solution structure consists of a dimer of helix-loop-helix motifs related by a 2-fold axis of symmetry. The overall architecture of the dimer is very similar to the C-terminal domain in the crystal structure of chicken skeletal troponin C.
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http://dx.doi.org/10.1021/bi00231a031 | DOI Listing |
J Am Chem Soc
January 2025
Institut de Chimie de Strasbourg, CNRS UMR 7177, Université de Strasbourg, 4, rue Blaise Pascal, Strasbourg 67000, France.
The discovery of a stable organic radical formed under mild, clean, and efficient light-mediated conditions is reported. The structure of the stable acridinium-based radical photoproduct was unambiguously established by single-crystal X-ray diffraction, mass spectrometry, and in solution by EPR, UV/vis, and NMR spectroscopies. The photochemical mechanism of its formation has been elucidated by photophysical experiments coupled with EPR experiments and theoretical investigations.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi 110062, India.
In recent years, the increasing prevalence of viral infections such as dengue (DENV) and chikungunya (CHIKV) has emphasized the vital need for new diagnostic techniques that are not only quick and inexpensive but also suitable for point-of-care and home usage. Existing diagnostic procedures, while useful, sometimes have limits in terms of speed, mobility, and price, particularly in resource-constrained environments and during epidemics. To address these issues, this study proposes a novel technique that combines 3D printing technology with electrochemical biosensors to provide a highly sensitive, user-friendly, and customizable diagnostic platform.
View Article and Find Full Text PDFSmall
January 2025
DWI-Leibniz Institute for Interactive Materials e.V., RWTH Aachen University, Forckenbeckstr. 50, 52074, Aachen, Germany.
Compartmentalization is crucial for control over complex biological cascade reactions. In microgels, the formation of discrete compartments allows for simultaneous uptake and orthogonal release of physicochemically distinct drugs, among others. However, many state-of-the-art approaches yielding compartmentalized microgels require the use of specific, though not always biocompatible, components and temperatures well above the physiological range, which may damage possible biological cargo.
View Article and Find Full Text PDFMol Inform
January 2025
Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Corrensstr. 48, 48149, Muenster, Germany.
Primary carnitine deficiency (PCD) is a rare autosomal recessive genetic disorder caused by missense mutations in the SLC22A5 gene encoding the organic carnitine transporter novel type 2 (OCTN2). This study investigates the structural consequences of PCD-causing mutations, focusing on the N32S variant. Using an alpha-fold model, molecular dynamics simulations reveal altered interactions and dynamics suggesting potential mechanistic changes in carnitine transport.
View Article and Find Full Text PDFIntegr Cancer Ther
January 2025
Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China.
Objective: To observe the clinical efficacy of Dendrobium officinale in the treatment of radiotherapy-induced oral mucositis in nasopharyngeal carcinoma patients, and to explore its regulating effect on immune function and oral microbiota by comparing immune-related factors and oral microbiota before and after the intervention.
Methods: We conducted a randomized double-blinded controlled trial in Zhejiang Cancer Hospital. Sixty patients with nasopharyngeal cancer combined with radiotherapy-induced oral mucositis were randomly divided into a study group and control group, with 30 cases in each group The study group used compound vitamin B12 solution and Dendrobium tea drink, and the control group simply used compound vitamin B12 solution rinse.
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