γ-Glutamyltranspeptidase (GGT) is a dimeric protein that specifically catalyzes the transfer of γ-glutamyl in the optimum pH range of 8.5-9.0, but has poor in vitro stability under the alkaline conditions. In the present work, GGT was immobilized on a mesoporoustitania oxide whisker (MTWs) carrier to afford MTWs-GGT that was further modified with Pharmalyte (Phar) 8.0-10.5 to yield MTWs-GGT-Phar. Phar absorbed on MTWs-GGT to form a buffering layer with an isoelectric point of ∼9.2 that isolated the immobilized enzyme from the liquid bulk and significantly in proved the pH tolerance and stability of the immobilized GGT. The MTWs-GGT-Phar exhibited a stable enzyme activity in the pH range of 6.0-11.0 and an optimum temperature 10°C higher than GGT. Its pH stability at pH 11.0 and thermal stability at 50°C were respectively 23.7 times and 19.4 times higher than those of GGT. In addition, the affinity constant of MTWs-GGT-Phar towards GpNA (K) was 0.597mM, slightly lower than that of free GGT, indicating that Phar had a protective effect on the structure of GGT.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.04.050 | DOI Listing |
Food Chem X
December 2024
College of Food Sciences & Technology, Shanghai Ocean University, Shanghai 201306, China.
Starch has been recognized as a vital ingredient in surimi products due to its ability to absorb water, which reduces the deterioration of gels and water loss during freezing and thawing. However, it is essential to ascertain the role of starch in the formation of ice crystals and the texture of surimi gels. The impact of freeze-thaw cycles on the morphology and distribution of ice crystals, as well as the textural characteristics of gelatinized and ungelatinized starch-surimi gels was investigated.
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January 2025
Institute of Agricultural Engineering, ARO, Volcani Institute, Rishon LeZion, Israel.
Food and agricultural commodities endure consistent contamination by mycotoxins, low molecular weight fungal metabolites, which pose severe health implications to humans together with staggering economic losses. Herein, a ratiometric aptasensor was constructed using silver-coated porous silicon (Ag-pSi) used as an efficient surface-enhanced Raman scattering (SERS) substrate. The bioassay included direct detection of fumonisin B (FB), an abundant and widespread contaminant, by a specific aptamer sequence immobilized on the porous transducer.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Life Sciences, Imperial College, London, SW7 2AZ, UK.
Many cellular patterns exhibit a reaction-diffusion component, suggesting that Turing instability may contribute to pattern formation. However, biological gene-regulatory pathways are more complex than simple Turing activator-inhibitor models and generally do not require fine-tuning of parameters as dictated by the Turing conditions. To address these issues, we employ random matrix theory to analyze the Jacobian matrices of larger networks with robust statistical properties.
View Article and Find Full Text PDFJ Environ Manage
January 2025
BQE Water, Vancouver, BC, Canada.
Biological semi-passive mine water treatment technologies are used in the mining industry as an alternative to or in conjunction with active treatment systems to remediate mine impacted water (MIW) containing nitrate and selenium oxyanions such as selenate and selenite. In semi-passive biological treatment systems, MIW is pumped through a saturated, porous media (either a gravel bed or waste rock) which provides ample surface area for biofilm growth and the creation of anoxic, subaqueous environments. Additional nutrients and carbon sources are pumped into the system to encourage the growth of microbes that biochemically reduce selenate and selenite to insoluble reduced Se species such as selenium nanoparticles (SeNP) by respiring selenate and selenite.
View Article and Find Full Text PDFBiomacromolecules
January 2025
School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K.
Enzymes are attractive as catalysts due to their specificity and biocompatibility; however, their use in industrial and biomedical applications is limited by stability. Here, we present a facile approach for enzyme immobilization within "all-enzyme" hydrogels by forming photochemical covalent cross-links between the enzyme glucose oxidase. We demonstrate that the mechanical properties of the enzyme hydrogel can be tuned with enzyme concentration and the data suggests that the dimeric nature of glucose oxidase results in unusual gel formation behavior which suggests a degree of forced induced dimer dissociation and unfolding.
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