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Light-sensitive Ca-regulated photoproteins of ctenophores are single-chain polypeptide proteins of 206-208 amino acids in length comprising three canonical EF-hand Ca-binding sites, each of 12 contiguous residues. These photoproteins are a stable complex of apoprotein and 2-hydroperoxy adduct of coelenterazine. Addition of calcium ions to photoprotein is only required to trigger bright bioluminescence. However, in contrast to the related Ca-regulated photoproteins of jellyfish their capacity to bioluminescence disappears on exposure to light over the entire absorption spectral range of ctenophore photoproteins. Here, we describe protocols for expression of gene encoding ctenophore photoprotein in Escherichia coli cells, obtaining of the recombinant apoprotein of high purity and its conversion into active photoprotein with synthetic coelenterazine as well as determination of its sensitivity to calcium ions using light-sensitive Ca-regulated photoprotein berovin from ctenophore Beroe abyssicola as an illustrative case.
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http://dx.doi.org/10.1007/978-1-0716-3642-8_12 | DOI Listing |
Biochim Biophys Acta Biomembr
September 2025
Department of Pharmaceutical Sciences, University of Vienna, Josef-Holaubek-Platz 2, Vienna, Austria.. Electronic address:
Using the stable synthetic analogue 3-aza-dehydroxylysyl-phosphatidylglycerol (3adLPG), the putative role of native staphylococcal LPG in inhibiting the antibiotic daptomycin from binding to its target phosphatidylglycerol (PG), was investigated with respect to interfacial interactions between these lipids, daptomycin, and calcium ions. The influence of lipid monolayer/bilayer composition and interfacial ion concentrations upon the structure and integrity of model membranes were probed after daptomycin challenge using a combination of surface x-ray scattering techniques and fluorescence assays. In models representing the membrane composition of the daptomycin susceptible phenotype consisting of PG/3adLPG in a 7:3 M ratio, calcium ions drive the formation of two separate phases; Ca cross-linked PG/PG pairs and PG/3adLPG ion pairs.
View Article and Find Full Text PDFJ Leukoc Biol
September 2025
Laboratory of Immunobiology and Ionic Transport Regulation, Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Av. 25 de Julio 965, Villa de San Sebastián, 28045 Colima, México.
Ion channels are integral membrane proteins which facilitate rapid transport of small ions into and out of the cell and between organelles and cytosol. Cytolytic lymphocytes including natural killer (NK) cells principally kill virus-infected and cancer cells by releasing cytolytic granules within the immunological synapse, formed between target and effector cells. This process strongly depends on Ca2+ signaling, which in human NK cells is controlled by the phospholipase C (PLCγ)/inositol-1,4,5-triphospate receptor (IP3R)/calcium release-activated calcium channel (CRAC) axis.
View Article and Find Full Text PDFFront Cardiovasc Med
August 2025
Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
In the cardiovascular system, elastic fibres exert a fundamental role providing the long-range elasticity required for physiological functions. Elastic fibres are complex in composition and structure containing, in addition to elastin, a wide range of matrix components, such as microfibrillar proteins, calcium-binding proteins and glycosaminoglycans. Changes in composition and/or structure can affect the biomechanics of the tissue as well as the intrinsic affinity of elastin for Ca ions.
View Article and Find Full Text PDFSci Total Environ
September 2025
Department of Orthopedics and Traumatology, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, Luzhou, Sichuan Province, China. Electronic address:
The objective of this research was to use a network toxicology approach to examine the possible toxicity of the cigarette toxicants nicotine and coal tar that cause osteoporosis (OP) as well as its molecular processes. We determined the primary chemical structures and 128 targets of action of tar and nicotine using the Swiss Target Prediction, NP-MRD, and PubChem databases. We discovered that genes including DNAJB1, CCDC8, LINC00888, ATP6V1G1, MPV17L2, PPCS, and TACC1 had a disease prognostic guiding value by LASSO analysis and differential analysis of GEO microarray data.
View Article and Find Full Text PDFBioorg Chem
September 2025
Key Innovation Laboratory for Deep and Intensive Processing of Yanbian High Quality Beef (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Yanbian University, Yanji 133002, PR China; Department of Food Science and Technology, College of Agricultural, Yanbian Univ
In this study, bovine peptide‑calcium chelates (BBP-Ca) were prepared via enzymatic hydrolysis to generate peptides and fermentation to obtain soluble calcium ions, which were then chelated together. The structural characteristics of BBP-Ca were comprehensively analyzed using FTIR, SEM, and UV spectroscopy. Additionally, its antioxidant capacity was evaluated by examining its protective effects against oxidative stress-induced damage in Caco-2 cells.
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