The facultative intracellular pathogen Bartonella henselae is responsible for a broad range of clinical manifestations, including the formation of vascular tumors as a result of increased proliferation and survival of colonized endothelial cells. This remarkable interaction with endotoxin-sensitive endothelial cells and the apparent lack of septic shock are considered to be due to a reduced endotoxic activity of the B. henselae lipopolysaccharide. Here, we show that B. henselae ATCC 49882(T) produces a deep-rough-type lipopolysaccharide devoid of O-chain and report on its complete structure and Toll-like receptor-dependent biological activity. The major short-chain lipopolysaccharide was studied by chemical analyses, electrospray ionization, and matrix-assisted laser desorption/ionization mass spectrometry, as well as by NMR spectroscopy after alkaline deacylation. The carbohydrate portion of the lipopolysaccharide consists of a branched trisaccharide containing a glucose residue attached to position 5 of an alpha-(2-->4)-linked 3-deoxy-d-manno-oct-2-ulosonic acid disaccharide. Lipid A is a pentaacylated beta-(1'-->6)-linked 2,3-diamino-2,3-dideoxy-glucose disaccharide 1,4'-bisphosphate with two amide-linked residues each of 3-hydroxydodecanoic and 3-hydroxyhexadecanoic acids and one residue of either 25-hydroxyhexacosanoic or 27-hydroxyoctacosanoic acid that is O-linked to the acyl group at position 2'. The lipopolysaccharide studied activated Toll-like receptor 4 signaling only to a low extent (1,000-10,000-fold lower compared with that of Salmonella enterica sv. Friedenau) and did not activate Toll-like receptor 2. Some unusual structural features of the B. henselae lipopolysaccharide, including the presence of a long-chain fatty acid, which are shared by the lipopolysaccharides of other bacteria causing chronic intracellular infections (e.g. Legionella and Chlamydia), may provide the molecular basis for low endotoxic potency.
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http://dx.doi.org/10.1074/jbc.M313370200 | DOI Listing |
Food Chem
December 2024
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830017, China. Electronic address:
This study developed antimicrobial peptides (AMPs) from quinoa with high antibacterial activity and stability by mixed-bacteria fermentation. Furthermore, among 9 peptide fractions purified by membrane separation and chromatography, F1 could effectively inhibit the growth and propagation of bacterial microorganisms in apple juice. Subsequently, F1 identified LC-MS/MS as 95 peptides, molecular weights 494.
View Article and Find Full Text PDFFood Chem
December 2024
The Blue Chemistry Lab Group, Department of Pharmacy, Università degli Studi di Napoli Federico II, Napoli, Italy. Electronic address:
Grape pomace (GP), a by-product of the wine supply chain process, contains bioactive molecules with known healthy properties. This study examines the impact of different extraction techniques on three GPs of Aglianico cultivar [Cantine del Notaio, Barile, and Torrecuso]. Five eco-friendly extractive techniques [maceration (MAC), digestion (DIG), accelerated solvent extraction (ASE), microwaves (MW), and ultrasound (US)] were used with 50 % ethanol/water as solvent.
View Article and Find Full Text PDFJ Phys Chem B
December 2024
State Key Laboratory of Physical Chemistry of Solid Surface, Key Laboratory of Chemical Biology of Fujian Province, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
Nucleation is a critical step that determines the assembly pathway and the structure and functions of the peptide assemblies. However, the dynamic evolution of interactions between nucleating agents and peptides, as well as between peptides themselves during the nucleation process, remains elusive. Herein, we show that the heterogeneous nucleating agent carboxymethylcellulose (CMC) can promote the nucleation of Aβ (KF) peptide.
View Article and Find Full Text PDFChemistry
December 2024
University of Copenhagen, Chemistry, Universitetsparken 5, Kemisk Institut, 2100, Copenhagen, DENMARK.
The atmospheric concentration of carbon dioxide (CO2) has fluctuated throughout Earth's history. However, the role of CO2 in prebiotic chemistry has predominantly been limitedly postulated as a C1 precursor, which can be reduced to carbon monoxide or methane mimicking the Wood-Ljungdahl pathway. Herein we present neglected roles of CO2 as an active promoter in accessing biologically important C3-builidng blocks such as lactate, via redox-economic reaction cycles from cyanide (C1) and acetaldehyde (C2).
View Article and Find Full Text PDFPLoS One
December 2024
Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon, Republic of Korea.
The increasing utilization of deep learning models in drug repositioning has proven to be highly efficient and effective. In this study, we employed an integrated deep-learning model followed by traditional drug screening approach to screen a library of FDA-approved drugs, aiming to identify novel inhibitors targeting the TNF-α converting enzyme (TACE). TACE, also known as ADAM17, plays a crucial role in the inflammatory response by converting pro-TNF-α to its active soluble form and cleaving other inflammatory mediators, making it a promising target for therapeutic intervention in diseases such as rheumatoid arthritis.
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