Amphidinol 3 (AM3) and theonellamide A (TNM-A) are potent antifungal compounds produced by the dinoflagellate Amphidinium klebsii and the sponge Theonella spp., respectively. Both of these metabolites have been demonstrated to interact with membrane lipids ultimately resulting in a compromised bilayer integrity. In this report, the activity of AM3 and TNM-A in ternary lipid mixtures composed of 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphocholine (POPC):brain sphingomyelin:cholesterol at a mole ratio of 1:1:1 or 3:1:1 exhibiting lipid rafts coexistence is presented. It was found that AM3 has a more extensive membrane permeabilizing activity compared with TNM-A in these membrane mimics, which was almost complete at 15 μM. The extent of their activity nevertheless is similar to the previously reported binary system of POPC and cholesterol, suggesting that phase separation has neither beneficial nor detrimental effects in their ability to disrupt the lipid bilayer.
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Antibiotics (Basel)
January 2025
Departamento de Química, Faculdade de Ciências Exatas, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Campus JK, Diamantina 39100-000, MG, Brazil.
This study investigates the structural and biophysical properties of the wild-type antimicrobial peptide LyeTx I, isolated from the venom of the spider , and its analog LyeTx I-b, designed to enhance antibacterial activity, selectivity, and membrane interactions by the acetylation and increased amphipathicty. : To understand the mechanisms behind these enhanced properties, comparative analyses of the structural, topological, biophysical, and thermodynamic aspects of the interactions between each peptide and phospholipid bilayers were evaluated. Both peptides were isotopically labeled with H-Ala and N-Leu to facilitate structural studies via NMR spectroscopy.
View Article and Find Full Text PDFMetabolites
January 2025
Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
Background/objectives: Early postmortem mitochondrial function and apoptotic activation affect meat quality development. Nicotinamide riboside (NR) supplementation to pigs prior to harvest can improve pork color stability, but its mechanism remains unclear. This study aimed to evaluate the impact of NR supplementation on early postmortem mitochondrial functionality and apoptosis.
View Article and Find Full Text PDFMicrob Pathog
January 2025
Postgraduate Program in Biological Sciences (PPGCB), Federal University of Pernambuco (UFPE), 50670-901, Recife, PE, Brazil. Electronic address:
The NorA and TetK efflux pumps mediate resistance to fluoroquinolone and tetracycline antibiotics by actively extruding these compounds and reducing their intracellular concentrations. Consequently, intense research has focused on inhibiting these efflux mechanisms using antimicrobial agents derived from natural or synthetic sources. This study used Fourier transform infrared spectroscopy (ATR-FTIR) to analyze the various functional groups present in p-coumaric acid.
View Article and Find Full Text PDFNat Protoc
January 2025
Joint Laboratory of Advanced Biomedical Materials (NFU-UGent), Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.
Photoporation with free photothermal nanoparticles (NPs) is a promising technology for gentle delivery of functional biomacromolecules into living cells, offering great flexibility in terms of cell types and payload molecules. However, the translational use of photoporation, such as for transfecting patient-derived cells for cell therapies, is hampered by safety and regulatory concerns as it relies on direct contact between cells and photothermal NPs. A solution is to embed the photothermal NPs in electrospun nanofibers, which form a substrate for cell culture.
View Article and Find Full Text PDFJ Physiol Sci
January 2025
Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-Ku, 116-8551, Tokyo, Japan. Electronic address:
Actin linked regulatory mechanisms are known to contribute contraction/relaxation in smooth muscle. In order to clarify whether modulation of polymerization/depolymerization of actin filaments affects relaxation process, we examined the effects of cytochalasin D on relaxation process by Ca removal after Ca-induced contraction of β-escin skinned (cell membrane permeabilized) taenia cecum and carotid artery preparations from guinea pigs. Cytochalasin D, an inhibitor of actin polymerization, significantly suppressed the force during relaxation both in skinned taenia cecum and carotid artery.
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