One mechanism by which bacteria can escape the action of beta-lactam antibiotics is the production of metallo-beta-lactamases. Inhibition of these enzymes should restore the action of these widely used antibiotics. The tetrameric enzyme L1 from Stenotrophomonas maltophilia was used as a model system to determine a series of high-resolution crystal structures of apo, mono and bi-metal substituted proteins as well as protein-inhibitor complexes. Unexpectedly, although the apo structure revealed only few significant structural differences from the holo structure, some inhibitors were shown to induce amino acid side-chain rotations in the tightly packed active site. Moreover, one inhibitor employs a new binding mode in order to interact with the di-zinc center. This structural information could prove essential in the process of elucidation of the mode of interaction between a putative lead compound and metallo-beta-lactamases, one of the main steps in structure-based drug design.
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http://dx.doi.org/10.1016/j.jmb.2007.10.036 | DOI Listing |
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 PDFNutrients
December 2024
IFF, Health & Biosciences, Sokeritehtaantie 20, 02460 Kantvik, Finland.
Background/objectives: Ergothioneine (EGT) is an effective antioxidant that animals cannot produce and has an important anti-inflammatory role in cell protection, which can help lower the risk of various diseases. In this study, we investigated the potential role of gut microbiota in the production of EGT, which was found to increase in the mouse liver after dietary supplementation with betaine (BET) or polydextrose (PDX).
Methods: The effects of BET and PDX on the gut microbiota and tissue EGT content were investigated using a diet-induced obese mouse model and simulated fermentation in the human colon.
Braz J Microbiol
January 2025
Department of Microbiology, Faculty of Science, Ain shams University, El-Khalyfa El-Mamoun Street, Abbasya, Cairo, Egypt.
Hospital surfaces are often contaminated with multidrug-resistant pathogenic bacteria that cause healthcare-associated infections and lead to increased mortality and morbidity. There is a need for new alternative antibacterial agents to overcome antibiotic resistance. Azadirachta indica and Simmondsia chinensis have been found to possess antibacterial activity and medicinal value.
View Article and Find Full Text PDFViruses
December 2024
Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Prosp. Lavrentieva 8, Novosibirsk 630090, Russia.
Anti-phage defense systems are widespread in bacteria due to the latter continuous adaptation to infection by bacteriophages (phages). has a high degree of intrinsic antibiotic resistance, which makes phage therapy relevant for the treatment of infections caused by this species. Studying the array of anti-phage defense systems that could be found in helps in better adapting the phages to the systems present in the pathogenic bacteria.
View Article and Find Full Text PDFToxics
December 2024
Postgraduate Program in Biotechnology and Biosciences, Department of Microbiology, Immunology and Parasitology, Federal University of Santa Catarina-Campus Reitor João David Ferreira Lima, Florianópolis 88040-900, SC, Brazil.
Bioremediation, involving the strategic use of microorganisms, has proven to be a cost-effective alternative for restoring areas impacted by persistent contaminants such as polycyclic aromatic hydrocarbons (PAHs). In this context, the aim of this study was to explore hydrocarbon-degrading microbial consortia by prospecting native species from soils contaminated with blends of diesel and biodiesel (20% biodiesel/80% diesel). After enrichment in a minimal medium containing diesel oil as the sole carbon source and based on 16S rRNA, Calmodulin and β-tubulin gene sequencing, seven fungi and 12 bacteria were identified.
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