ClyA is a pore-forming toxin from virulent Escherichia coli and Salmonella enterica strains. Here, we show that the intrinsic hemolytic activity of ClyA is independent of its redox state, and that the assembly of both reduced and oxidized ClyA to the ring-shaped oligomer is triggered by contact with lipid or detergent. A rate-limiting conformational transition in membrane-bound ClyA monomers precedes their assembly to the functional pore. We obtained a three-dimensional model of the detergent-induced oligomeric complex at 12 A resolution by combining cryo- and negative stain electron microscopy with mass measurements by scanning transmission electron microscopy. The model reveals that 13 ClyA monomers assemble into a cylinder with a hydrophobic cap region, which may be critical for membrane insertion.
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http://dx.doi.org/10.1038/sj.emboj.7601130 | DOI Listing |
Infect Dis (Lond)
January 2025
Infectious Diseases, KIMS ICON Hospital, Visakhapatnam, Andhra Pradesh, India.
Background: This study was done with objectives of determining the predictors of mortality in patients with Gram-Negative Bacilli (GNB) Blood stream Infection (BSI) along with estimating mortality attributable to carbapenem resistance (CR).
Methods: In this prospective cohort study (January 2023-September 2024), done in 3 tertiary care centres in India, patients found to have mono-microbial GNB BSI were included. Primary outcome was crude mortality at day 30 of onset of BSI.
The Stenotrophomonas maltophilia L2 cephalosporinase is one of two beta-lactamases which afford S. maltophilia beta-lactam resistance. With the overuse of beta-lactams, selective pressures have contributed to the evolution of these proteins, generating proteins with an extended spectrum of activity.
View Article and Find Full Text PDFFood Funct
January 2025
Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, People's Republic of China.
Inflammatory bowel disease (IBD) is a chronic inflammation with a high incidence rate. Many probiotics, including (), have shown promise in IBD treatment. The therapeutic effects of most probiotics are greatly decided by the available live cells in the disease lesion, which is compromised as they pass through the gastric juice and intestinal tract, resulting in a loss of activity.
View Article and Find Full Text PDFJ Antimicrob Chemother
January 2025
Bristol Centre for Antimicrobial Research & Evaluation (BCARE), Infection Sciences, Southmead Hospital, Westbury-on-Trym, Bristol, UK.
Background: NOSO-5O2 is the first clinical candidate of a new antimicrobial class-the odilorhabdins. The pharmacodynamics of NOSO-502 were studied in vitro and in vivo to establish the pharmacodynamic index (PDI) driver.
Methods: A dilutional pharmacokinetic system was used for in vitro experiments.
Brief Bioinform
November 2024
Department of Biology, University at Albany, SUNY, 1400 Washington Ave, Albany, NY 12222, United States.
The accuracy of assigning fluorophore identity and abundance, known as spectral unmixing, in biological fluorescence microscopy images remains a significant challenge due to the substantial overlap in emission spectra among fluorophores. In traditional laser scanning confocal spectral microscopy, fluorophore information is acquired by recording emission spectra with a single combination of discrete excitation wavelengths. However, organic fluorophores possess characteristic excitation spectra in addition to their unique emission spectral signatures.
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