Polysaccharide Utilization Loci (PULs) are physically linked gene clusters conserved in the Gram-negative phylum of Bacteroidota and are valuable sources for Carbohydrate Active enZyme (CAZyme) discovery. This study focuses on BD-β-Gal, an enzyme encoded in a metagenomic PUL and member of the Glycoside Hydrolase family 154 (GH154). BD-β-Gal showed exo-β-galactosidase activity with regiopreference for hydrolyzing β-d-(1,6) glycosidic linkages. Notably, it exhibited a preference for d-glucopyranosyl (d-Glcp) over d-galactopyranosyl (d-Galp) and d-fructofuranosyl (d-Fruf) at the reducing end of the investigated disaccharides. In addition, we determined the high resolution crystal structure of BD-β-Gal, thus providing the first structural characterization of a GH154 enzyme. Surprisingly, this revealed an (α/α) topology, which has not been observed before for β-galactosidases. BD-β-Gal displayed low structural homology with characterized CAZymes, but conservation analysis suggested that the active site was located in a central cavity, with conserved E73, R252, and D253 as putative catalytic residues. Interestingly, BD-β-Gal has a tetrameric structure and a flexible loop from a neighboring protomer may contribute to its reaction specificity. Finally, we showed that the founding member of GH154, BT3677 from Bacteroides thetaiotaomicron, described as β-glucuronidase, displayed exo-β-galactosidase activity like BD-β-Gal but lacked a tetrameric structure.
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http://dx.doi.org/10.1016/j.nbt.2023.12.011 | DOI Listing |
Sci Rep
December 2024
School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China.
Microtextured microneedles are tiny needle-like structures with micron-scale microtextures, and the drugs stored in the microtextures can be released after entering the skin to achieve the effect of precise drug delivery. In this study, the skin substitution model of Ogden's hyperelastic model and the microneedle array and microtexture models with different geometrical parameters were selected to simulate and analyse the flow of the microtexture microneedle arrays penetrating the skin by the finite-element method, and the length of the microneedles was determined to be 200 μm, the width 160 μm, and the value of the gaps was determined to be 420 μm. A four-pronged cone was chosen as the shape of microneedles, and a rectangle was chosen as the shape of the drug-carrying microneedle.
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December 2024
Department of Electronics, Carleton University, Ottawa, ON, K1S 5B6, Canada.
In this paper, we propose a novel structure of anisotropic graphene-based hyperbolic metamaterial (AGHMM) sandwiched as a defect between two one-dimensional photonic crystals (PCs) in the terahertz (THz) region. The proposed structure is numerically simulated and analyzed using the transfer matrix method, effective medium theory and three-dimensional finite-difference time-domain. The defect layer of AGHMM consists of graphene sheets separated by subwavelength dielectric spacers.
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December 2024
Institut Laue-Langevin, 71, av des Martyrs CS 20156, Grenoble, 38042, France.
The promise of antiferromagnetic spintronics largely relies on the possibilities of electrical manipulation of antiferromagnetic states, which requires the exploration of innovative material platforms to meet the challenge. Erythrosiderite-type compounds constitute a class of non-oxide materials presenting magneto-electric couplings ranging from multiferroicity to linear magneto-electric behaviour. In this communication, we demonstrate that Cs[FeCl(DO)] shows evidence of another ferroic order, ferrotoroidicity, providing an alternative way of manipulating the magnetic states.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Food and Nutritional Sciences Program, North Carolina Agricultural and Technical State University, Greensboro, NC, USA.
A chicken protein hydrogel (HG) was enzymatically prepared and blended with a carnauba wax-based oleogel (OG) to form bigels (BG) in ratios of 50:50 to 90:10. These systems were infused with thyme essential oil (TEO) at 0.5 %, 1 %, and 2 % v/v to harness its antioxidant properties.
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December 2024
School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Parkville, Vic 3010, Australia. Electronic address:
This work examined the effects of molecular weight (2-15 kDa) and concentration (10-30 mg/mL) of chitosan (CTS) on the binding capacity and interface behavior between octenyl succinic acid sodium starch (OSS) and CTS, as well as their effects on the storage stability of emulsions. The results of the isothermal calorimetry titration demonstrated that OSS and CTS were complexed by electrostatic interaction and spontaneous hydrogen bonding driven by enthalpy (ΔH from -3931 to -7983 cal/mol, ΔS from -38.5 to -49.
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