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21.
《Mendeleev Communications》2022,32(5):667-669
Microporous hydrophobic silicalite-1 was used as a carrier for immobilization of different enzymes, such as horseradish peroxidase, calf intestinal alkaline phosphatase and two β-galactosidases of different origin, to create heterogeneous biocatalytic systems. The peculiarities of enzyme adsorption on the surface of silicalite-1, as well as catalytic properties of the obtained systems compared to enzyme activity in solution and on the surface of other carriers, are discussed. 相似文献
22.
Jung-Young Park Gu-Hwan Kim Sung-Su Kim Jung Min Ko Jin-Joo Lee Han-Wook Yoo 《Experimental & molecular medicine》2009,41(1):1-7
Fabry disease is an X-linked inborn error of glycosphingolipid catabolism that results from mutations in the gene encoding the α-galactosidase A (GLA) enzyme. We have identified 15 distinct mutations in the GLA gene in 13 unrelated patients with classic Fabry disease and 2 unrelated patients with atypical Fabry disease. Two of the identified mutations were novel (i.e., the D231G missense mutation and the L268delfsX1 deletion mutation). This study evaluated the effects of the chemical chaperones 1-deoxygalactonojirimycin (DGJ) on the function of GLA in vitro, in cells containing missense mutations in the GLA gene. Nine missense and a nonsense mutations, including one novel mutation were cloned into mammalian expression vectors. After transient expression in COS-7 cells, GLA enzyme activity and protein expression were analyzed using fluorescence spectrophotometry and Western blot analysis, respectively. DGJ enhanced GLA enzyme activity in the M42V, I91T, R112C and F113L mutants. Interestingly, the I91T and F113L mutations are associated with the atypical form of Fabry disease. However, DGJ treatment did not have any significant effect on the GLA enzyme activity and protein expression of other mutants, including C142W, D231G, D266N, and S297F. Of note, GLA enzyme activity was not detected in the novel mutant (i.e., D231G), although protein expression was similar to the wild type. In the absence of DGJ, the E66Q mutant had wild-type levels of GLA protein expression and approximately 40% GLA activity, indicating that E66Q is either a mild mutation or a functional single nucleotide polymorphism (SNP). Thus, the results of this study suggest that the chemical chaperone DGJ enhances GLA enzyme activity and protein expression in milder mutations associated with the atypical form of Fabry disease. 相似文献
23.
Laura M. Lilley Sarah Kamper Michael Caldwell Zer Keen Chia David Ballweg Luke Vistain Jeffrey Krimmel Teresa Anne Mills Keith MacRenaris Paul Lee Emily Alexandria Waters Thomas J. Meade 《Angewandte Chemie (International ed. in English)》2020,59(1):388-394
Our lab has developed a new series of self‐immolative MR agents for the rapid detection of enzyme activity in mouse models expressing β‐galactosidase (β‐gal). We investigated two molecular architectures to create agents that detect β‐gal activity by modulating the coordination of water to GdIII. The first is an intermolecular approach, wherein we designed several structural isomers to maximize coordination of endogenous carbonate ions. The second involves an intramolecular mechanism for q modulation. We incorporated a pendant coordinating carboxylate ligand with a 2, 4, 6, or 8 carbon linker to saturate ligand coordination to the GdIII ion. This renders the agent ineffective. We show that one agent in particular (6‐C pendant carboxylate) is an extremely effective MR reporter for the detection of enzyme activity in a mouse model expressing β‐gal. 相似文献
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25.
Luigi Tavernini Oscar Romero Carla Aburto Fernando Lpez-Gallego Andrs Illanes Lorena Wilson 《Molecules (Basel, Switzerland)》2021,26(14)
Hybrid bioinorganic biocatalysts have received much attention due to their simple synthesis, high efficiency, and structural features that favor enzyme activity and stability. The present work introduces a biomineralization strategy for the formation of hybrid nanocrystals from β-galactosidase. The effects of the immobilization conditions were studied, identifying the important effect of metal ions and pH on the immobilization yield and the recovered activity. For a deeper understanding of the biomineralization process, an in silico study was carried out to identify the ion binding sites at the different conditions. The selected β-galactosidase nanocrystals showed high specific activity (35,000 IU/g biocatalyst) and remarkable thermal stability with a half-life 11 times higher than the soluble enzyme. The nanobiocatalyst was successfully tested for the synthesis of galacto-oligosaccharides, achieving an outstanding performance, showing no signs of diffusional limitations. Thus, a new, simple, biocompatible and inexpensive nanobiocatalyst was produced with high enzyme recovery (82%), exhibiting high specific activity and high stability, with promising industrial applications. 相似文献
26.
Praveen K. Gulaka Jian-Xin Yu Li Liu Ralph P. Mason Vikram D. Kodibagkar 《Magnetic resonance imaging》2013
The quantitative assessment of gene expression and related enzyme activity in vivo could be important for the characterization of gene altering diseases and therapy. The development of imaging techniques, based on specific reporter molecules may enable routine non-invasive assessment of enzyme activity and gene expression in vivo. We recently reported the use of commercially available S-Gal® as a β-galactosidase reporter for 1H MRI, and the synthesis of several S-Gal® analogs with enhanced response to β-galactosidase activity. We have now compared these analogs in vitro and have identified the optimal analog, C3-GD, based on strong T1 and T2 response to enzyme presence (ΔR1 and ΔR2 ~ 1.8 times S-Gal®). Moreover, application is demonstrated in vivo in human breast tumor xenografts. MRI studies in MCF7-lacZ tumors implanted subcutaneously in athymic nude mice (n = 6), showed significant reduction in T1 and T2 values (each ~ 13%) 2 h after intra-tumoral injection of C3-GD, whereas the MCF7 (wild type) tumors showed slight increase. Thus, C3-GD successfully detects β-galactosidase activity in vivo and shows promise as a lacZ gene 1H MR reporter molecule. 相似文献
27.
The paper presents the results of investigations into the technological possibilities of controlling the transgalactosylation
process of lactose in permeate after whey ultrafiltration in order to improve the efficiency of galactooligosaccharides or
lactulose synthesis. The synthesis efficiency was influenced by the selection of a β-galactosidase preparation, substrate
concentration and, in the synthesis of lactulose, also by the ratio of lactose and fructose added to the reaction mixture.
The obtained synthesis efficiency of GOS and, most of all, of lactulose (65 g L−1), may be found satisfactory. The study also resulted in a proposed GOS or lactulose concentrates (concentrated or dried)
production technology using permeate after ultrafiltration of milk or whey as lactose sources.
Presented at the 35th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 26–30 May
2008. 相似文献
28.
α-Galactosidase (EC 3.2.1.22) refers to a group of enzymes that hydrolyze oligosaccharides containing α-galactoside-banded glycosides, such as stachyose, raffinose, and verbascose. These enzymes also possess great potential for application in sugar production, and in the feed and pharmaceutical industries. In this study, a strain of Lactosphaera pasteurii (WHPC005) that produces α-galactosidase was identified from the soil of Western Hunan, China. It was determined that the optimal temperature and pH for this α-galactosidase were 45 °C and 5.5, respectively. The activity of α-galactosidase was inhibited by K+, Al3+, Fe3+, fructose, sucrose, lactose, galactose, SDS, EDTA, NaCl, and (NH4)2SO4, and enhanced by Ca2+, Fe2+, Mn2, Zn2+, glucose, and raffinose. The optimal inducer was raffinose, and the optimal induction concentration was 30 μmol/L. The α-galactosidase gene was cloned using random fragment cloning methods. Sequence analysis demonstrated that the open reading frame of the α-galactosidase gene was 1230 bp, which encodes a putative protein of 409 amino acids in length. Bioinformatics analysis showed that the isoelectric point and molecular weight of this α-galactosidase were 4.84 and 47.40 kD, respectively. Random coils, alpha helixes, and beta turns were observed in its secondary structure, and conserved regions were found in the tertiary structure of this α-galactosidase. Therefore, this α-galactosidase-producing bacterial strain has the potential for application in the feed industry. 相似文献
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Lenka Weignerov Petr Sedmera Zdenka Hukov Petr Halada Vladimír Ken Monica Casali Sergio Riva 《Tetrahedron letters》1999,40(52):65
6′-O-Acyl-lactose derivatives (1b-d) were prepared by selective enzymatic acylation of lactose using the protease subtilisin. These compounds were used as acceptors for enzymatic transglycosylations catalysed by an α-galactosidase from Talaromyces flavus forming (after deacylation) iso-globotriose (α-d-Galp-(1→3)-β-d-Galp-(1→4)Glc, 2a). 相似文献