Various bacterial pathogens are producing toxins that target the cyclic Nucleotide Monophosphate (cNMPs) signaling pathways in order to facilitate host colonization. Among them, several are exhibiting potent nucleotidyl cyclase activities that are activated by eukaryotic factors, such as the adenylate cyclase (AC) toxin, CyaA, from or the edema factor, EF, from . The characterization of these toxins frequently requires accurate measurements of their enzymatic activity in vitro, in particular for deciphering their structure-to-function relationships by protein engineering and site-directed mutagenesis. Here we describe a simple and robust in vitro assay for AC activity based on the spectrophotometric detection of cyclic AMP (cAMP) after chromatographic separation on aluminum oxide. This assay can accurately detect down to fmol amounts of CyaA and can even be used in complex media, such as cell extracts. The relative advantages and disadvantages of this assay in comparison with other currently available methods are briefly discussed.
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http://dx.doi.org/10.3390/toxins14100691 | DOI Listing |
Cell Biol Toxicol
January 2025
Department of Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, 8600, Dübendorf, Switzerland.
Advancing in vitro systems to address the effects of chemical pollution requires a thorough characterization of their functionalities, such as their repertoire of biotransformation enzymes. Currently, knowledge regarding the presence, activity magnitudes, and inducibility of different biotransformation pathways in vitro is scarce, particularly across organs. We report organ-specific kinetics for phase I and II biotransformation enzymes, under basal and induced conditions, in two in vitro systems using salmonid fish: S9 sub-cellular fractions from brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) were compared with rainbow trout cell lines.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
January 2025
Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
The fermentative production of valuable chemicals from lignocellulosic feedstocks has attracted considerable attention. Although Saccharomyces cerevisiae is a promising microbial host, it lacks the ability to efficiently metabolize xylose, a major component of lignocellulosic feedstocks. The xylose oxidative pathway offers advantages such as simplified metabolic regulation and fewer enzymatic steps.
View Article and Find Full Text PDFLasers Med Sci
January 2025
The Department of Preventive Dentistry, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, 646000, China.
The purpose of this study was to examine how low-energy LED red light influences the early to middle stage of osteogenic differentiation of periodontal ligament stem cells (PDLSCs) via the ERK5 signaling pathway. METHODS: PDLSCs were extracted from periodontal membrane tissue using enzymatic digestion. At three time points of 7, 10, and 14 days after irradiation with 5J/cm LED red light, the expression levels of early to middle-stage osteogenic-related genes ALP, Col-1, BSP, and OPN were detected by real-time fluorescence quantitative PCR(qRT-PCR) in both control and osteogenesis experimental groups.
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January 2025
Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, Texas, USA.
Unlabelled: Human norovirus (HuNoV) is a leading cause of gastroenteritis worldwide and is associated with significant morbidity, mortality, and economic impact. There are currently no licensed antiviral drugs for the treatment of HuNoV-associated gastroenteritis. The HuNoV protease plays a critical role in the initiation of virus replication by cleaving the polyprotein.
View Article and Find Full Text PDFNanoscale
January 2025
School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science (IACS), 2A and 2B Raja. S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
Water-soluble π-conjugated luminescent bioprobes have been broadly used in biomedical research but are limited by the nonbiodegradability associated with their rigid C-C backbones. In the present work, we introduced three naphthalene monoimide (NMI)-functionalized amphiphilic fluorescent polyesters (P1, P2, and P3) prepared by transesterification of functional diols with an activated diester monomer of adipic acid. These polyesters featured a side-chain NMI fluorophore, imparting the required hydrophobicity for self-assembly in water and endowing the polymeric nanoassemblies with green fluorescence.
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