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1.
Small ; 20(26): e2308861, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38372029

RESUMO

The anabolism of tumor cells can not only support their proliferation, but also endow them with a steady influx of exogenous nutrients. Therefore, consuming metabolic substrates or limiting access to energy supply can be an effective strategy to impede tumor growth. Herein, a novel treatment paradigm of starving-like therapy-triple energy-depleting therapy-is illustrated by glucose oxidase (GOx)/dc-IR825/sorafenib liposomes (termed GISLs), and such a triple energy-depleting therapy exhibits a more effective tumor-killing effect than conventional starvation therapy that only cuts off one of the energy supplies. Specifically, GOx can continuously consume glucose and generate toxic H2O2 in the tumor microenvironment (including tumor cells). After endocytosis, dc-IR825 (a near-infrared cyanine dye) can precisely target mitochondria and exert photodynamic and photothermal activities upon laser irradiation to destroy mitochondria. The anti-angiogenesis effect of sorafenib can further block energy and nutrition supply from blood. This work exemplifies a facile and safe method to exhaust the energy in a tumor from three aspects and starve the tumor to death and also highlights the importance of energy depletion in tumor treatment. It is hoped that this work will inspire the development of more advanced platforms that can combine multiple energy depletion therapies to realize more effective tumor treatment.


Assuntos
Glucose Oxidase , Lipossomos , Sorafenibe , Lipossomos/química , Humanos , Glucose Oxidase/metabolismo , Glucose Oxidase/química , Animais , Sorafenibe/farmacologia , Linhagem Celular Tumoral , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Metabolismo Energético , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/química , Indóis
2.
Chembiochem ; : e202400390, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-39031725

RESUMO

Hydrogen polysulfides (H2Sn) have emerged as critical physiological mediators that are closely associated with hydrogen sulfide (H2S) signaling. H2Sn exhibit greater nucleophilicity than H2S while also having electrophilic characteristics, enabling unique activities such as protein S-persulfidation. Despite their physiological importance, mechanisms and reactivities of H2Sn remain inadequately explored due to their inherent instability in aqueous environments. Consequently, there is a need to develop biocompatible methods for controlled H2Sn generation to elucidate their behaviors in biological contexts. Herein, we present a dual enzyme system (containing glucose oxidase (GOx) and chloroperoxidase (CPO)) with thioglucose as the substrate to facilitate the controlled release of H2Sn. Fluorescence measurements with SSP4 and the trapping studies allowed us to confirm the production of H2Sn. Such a method may be useful in elucidating the reactivity of hydrogen polysulfides in biological systems as well as provide a potential delivery of H2Sn to target sites for biological applications.

3.
Biotechnol Bioeng ; 121(1): 219-227, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37807712

RESUMO

Methods for culturing oxygen-sensitive cells and organisms under anaerobic conditions are vital to biotechnology research. Here, we report a biomaterial-based platform for anaerobic culture that consists of glucose oxidase (GOX) functionalized alginate microparticles (ALG-GOX), which are designed to deplete dissolved [O2 ] through enzymatic activity. ALG-GOX microparticles were synthesized via a water-in-oil emulsion and had a size of 132.0 ± 51.4 µm. Despite having a low storage modulus, the microparticles remained stable under aqueous conditions due to covalent crosslinking through amide bonds. Enzyme activity was tunable based on the loaded GOX concentration, with a maximum activity of 3.6 ± 0.3 units/mg of microparticles being achieved at an initial loading concentration of 5 mg/mL of GOX in alginate precursor solution. High enzyme activity in ALG-GOX microparticles resulted in rapid oxygen depletion, producing a suitable environment for anaerobic culture. Microparticles loaded with both GOX and catalase (ALG-GOX-CAT) to reduce H2 O2 buildup exhibited sustained activity for potential long-term anaerobic culture. ALG-GOX-CAT microparticles were highly effective for the anaerobic culture of Bacteroides thetaiotaomicron, with 10 mg/mL of ALG-GOX-CAT microparticles supporting the same level of growth in an aerobic environment compared to an anaerobic chamber after 16 h (8.70 ± 0.96 and 10.03 ± 1.03 million CFU, respectively; N.S. p = 0.07). These microparticles could be a valuable tool for research and development in biotechnology.


Assuntos
Alginatos , Técnicas de Cultura de Células , Alginatos/química , Anaerobiose , Glucose Oxidase/química
4.
Biotechnol Bioeng ; 121(2): 735-748, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38037762

RESUMO

Glucose oxidase (EC 1.1.3.4, GOD) is a widely used industrial enzyme. To construct a GOD-hyperproducing Pichia pastoris strain, combinatorial strategies have been applied to improve GOD activity, synthesis, and secretion. First, wild-type GOD was subjected to saturation mutagenesis to obtain an improved variant, MGOD1 (V20W/T30S), with 1.7-fold higher kcat /KM . Subsequently, efficient signal peptides were screened, and the copy number of MGOD1 was optimized to generate a high-producing strain, 8GM1, containing eight copies of AOX1 promoter-GAS1 signal peptide-MGOD1 expression cassette. Finally, the vesicle trafficking of 8GM1 was engineered to obtain the hyperproducing strain G1EeSe co-expressing the trafficking components EES and SEC. 22, and the EES gene (PAS_chr3_0685) was found to facilitate both protein secretion and production for the first time. Using these strategies, GOD secretion was enhanced 65.2-fold. In the 5-L bioreactor, conventional fed-batch fermentation without any process optimization resulted in up to 7223.0 U/mL extracellular GOD activity (3.3-fold higher than the highest level reported to date), with almost only GOD in the fermentation supernatant at a protein concentration of 30.7 g/L. Therefore, a GOD hyperproducing strain for industrial applications was developed, and this successful case can provide a valuable reference for the construction of high-producing strains for other industrial enzymes.


Assuntos
Glucose Oxidase , Pichia , Saccharomycetales , Glucose Oxidase/genética , Glucose Oxidase/metabolismo , Pichia/metabolismo , Reatores Biológicos , Fermentação , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
5.
Microb Cell Fact ; 23(1): 76, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461254

RESUMO

BACKGROUND: Aspergillus niger ATCC 20611 is an industrially important fructooligosaccharides (FOS) producer since it produces the ß-fructofuranosidase with superior transglycosylation activity, which is responsible for the conversion of sucrose to FOS accompanied by the by-product (glucose) generation. This study aims to consume glucose to enhance the content of FOS by heterologously expressing glucose oxidase and peroxidase in engineered A. niger. RESULTS: Glucose oxidase was successfully expressed and co-localized with ß-fructofuranosidase in mycelia. These mycelia were applied to synthesis of FOS, which possessed an increased purity of 60.63% from 52.07%. Furthermore, peroxidase was expressed in A. niger and reached 7.70 U/g, which could remove the potential inhibitor of glucose oxidase to facilitate the FOS synthesis. Finally, the glucose oxidase-expressing strain and the peroxidase-expressing strain were jointly used to synthesize FOS, which content achieved 71.00%. CONCLUSIONS: This strategy allows for obtaining high-content FOS by the multiple enzymes expressed in the industrial fungus, avoiding additional purification processes used in the production of oligosaccharides. This study not only facilitated the high-purity FOS synthesis, but also demonstrated the potential of A. niger ATCC 20611 as an enzyme-producing cell factory.


Assuntos
Aspergillus niger , Aspergillus , beta-Frutofuranosidase , Aspergillus niger/genética , Glucose Oxidase/genética , Oligossacarídeos , Peroxidases , Glucose
6.
Anal Bioanal Chem ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38739158

RESUMO

Nanozymes are nanomaterials with mimetic enzyme properties and the related research has attracted much attention. It is of great value to develop methods to construct nanozymes and to study their application in bioanalysis. Herein, the metal-ligand cross-linking strategy was developed to fabricate superstructure nanozymes. This strategy takes advantage of being easy to operate, adjustable, cheap, and universal. The fabricated superstructure nanozymes possess efficient peroxidase-like catalytic activity. The enzyme reaction kinetic tests demonstrated that for TMB and H2O2, the Km is 0.229 and 1.308 mM, respectively. Furthermore, these superstructure nanozymes are applied to highly efficient and sensitive detection of glucose. The linear range for detecting glucose is 20-2000 µM, and the limit of detection is 17.5 µM. Furthermore, mechanistic research illustrated that this integrated system oxidizes glucose to produce hydrogen peroxide and further catalyzes the production of ·OH and O2·-, which results in a chromogenic reaction of oxidized TMB for the detection of glucose. This work could not only contribute to the development of efficient nanozymes but also inspire research in the highly sensitive detection of other biomarkers.

7.
Environ Res ; 247: 118257, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38262511

RESUMO

This study introduces the UV/glucose-oxidase@Kaolin (GOD@Kaolin) coupled organic green rust (OGR) system (UV/OGR/GOD@Kaolin) to investigate the promotion of glucose oxidase activity by UV light and its synergistic degradation mechanism for photosensitive pollutants, specifically targeting the efficient degradation of 4-chlorophenol (4-CP). The enzyme system demonstrates its ability to overcome drawbacks associated with traditional Fenton systems, including a narrow pH range and high localized concentration of H2O2, by gradually releasing hydrogen peroxide in situ within a neutral environment. In the presence of UV radiation under specific conditions, enhanced enzyme activity is observed, resulting in increased efficiency in pollutant removal. The gradual release of hydrogen peroxide plays a crucial role in preventing unwanted reactions among active substances. These unique features facilitate the generation of highly reactive species, such as Fe(IV)O, •OH, and •O2-, tailored to efficiently target the organic components of interest. Additionally, the system establishes a positive iron cycle, ensuring a sustained reactive capability throughout the degradation process. The results highlight the UV/OGR/GOD@Kaolin system as an effective and environmentally friendly approach for the degradation of 4-CP, and the resilience of the enzyme extends the system's applicability to a broader range of scenarios.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Raios Ultravioleta , Peróxido de Hidrogênio/química , Glucose Oxidase/metabolismo , Caulim , Glucose , Oxirredução , Poluentes Químicos da Água/química
8.
Appl Microbiol Biotechnol ; 108(1): 48, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38183481

RESUMO

Oxygen is crucial for converting glucose to gluconic acid catalyzed by glucose oxidase (Gox). However, industrial gluconic acid production faces oxygen supply limitations. To enhance Gox efficiency, Vitreoscilla hemoglobin (VHb) has been considered as an efficient oxygen transfer carrier. This study identified GoxA, a specific isoform of Gox in the industrial gluconic acid-producing strain of Aspergillus niger. Various forms of VHb expression in A. niger were tested to improve GoxA's catalytic efficiency. Surprisingly, the expression of free VHb, both intracellularly and extracellularly, did not promote gluconic acid production during shake flask fermentation. Then, five fusion proteins were constructed by linking Gox and VHb using various methods. Among these, VHb-GS1-GoxA, where VHb's C-terminus connected to GoxA's N-terminus via the flexible linker GS1, demonstrated a significantly higher Kcat/Km value (96% higher) than GoxA. Unfortunately, the expression of VHb-GS1-GoxA in A. niger was limited, resulting in a low gluconic acid production of 3.0 g/L. To overcome the low expression problem, single- and dual-strain systems were designed with tools of SpyCatcher/SpyTag and SnoopCatcher/SnoopTag. In these systems, Gox and VHb were separately expressed and then self-assembled into complex proteins. Impressively, the single-strain system outperformed the GoxA overexpression strain S1971, resulting in 23% and 9% higher gluconic acid production under 0.6 vvm and 1.2 vvm aeration conditions in the bioreactor fermentation, respectively. The successful construction of Gox and VHb fusion or complex proteins, as proposed in this study, presents promising approaches to enhance Gox catalytic efficiency and lower aerodynamic costs in gluconic acid production. KEY POINTS: • Overexpressing free VHb in A. niger did not improve the catalytic efficiency of Gox • The VHb-GS1-GoxA showed an increased Kcat/Km value by 96% than GoxA • The single-strain system worked better in the gluconic acid bioreactor fermentation.


Assuntos
Aspergillus niger , Glucose Oxidase , Aspergillus niger/genética , Glucose Oxidase/genética , Catálise , Oxigênio
9.
Nanomedicine ; 61: 102764, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38885751

RESUMO

Glucose oxidase (GOx) is often used to starvation therapy. However, only consuming glucose cannot completely block the energy metabolism of tumor cells. Lactate can support tumor cell survival in the absence of glucose. Here, we constructed a nanoplatform (Met@HMnO2-GOx/HA) that can deplete glucose while inhibiting the compensatory use of lactate by cells to enhance the effect of tumor starvation therapy. GOx can catalyze glucose into gluconic acid and H2O2, and then HMnO2 catalyzes H2O2 into O2 to compensate for the oxygen consumed by GOx, allowing the reaction to proceed sustainably. Furthermore, metformin (Met) can inhibit the conversion of lactate to pyruvate in a redox-dependent manner and reduce the utilization of lactate by tumor cells. Met@HMnO2-GOx/HA nanoparticles maximize the efficacy of tumor starvation therapy by simultaneously inhibiting cellular utilization of two carbon sources. Therefore, this platform is expected to provide new strategies for tumor treatment.

10.
Bioprocess Biosyst Eng ; 47(6): 919-929, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38644439

RESUMO

The growing need in the current market for innovative solutions to obtain lactose-free (L-F) milk is caused by the annual increase in the prevalence of lactose intolerance inside as well as the newborn, children, and adults. Various configurations of enzymes can yield two distinct L-F products: sweet (ß-galactosidase) and unsweet (ß-galactosidase and glucose oxidase) L-F milk. In addition, the reduction of sweetness through glucose decomposition should be performed in a one-pot mode with catalase to eliminate product inhibition caused by H2O2. Both L-F products enjoy popularity among a rapidly expanding group of consumers. Although enzyme immobilization techniques are well known in industrial processes, new carriers and economic strategies are still being searched. Polymeric carriers, due to the variety of functional groups and non-toxicity, are attractive propositions for individual and co-immobilization of food enzymes. In the presented work, two strategies (with free and immobilized enzymes; ß-galactosidase NOLA, glucose oxidase from Aspergillus niger, and catalase from Serratia sp.) for obtaining sweet and unsweet L-F milk under low-temperature conditions were proposed. For free enzymes, achieving the critical assumption, lactose hydrolysis and glucose decomposition occurred after 1 and 4.3 h, respectively. The tested catalytic membranes were created on regenerated cellulose and polyamide. In both cases, the time required for lactose and glucose bioconversion was extended compared to free enzymes. However, these preparations could be reused for up to five (ß-galactosidase) and ten cycles (glucose oxidase with catalase).


Assuntos
Enzimas Imobilizadas , Glucose Oxidase , Lactose , Leite , beta-Galactosidase , beta-Galactosidase/metabolismo , beta-Galactosidase/química , Leite/química , Lactose/metabolismo , Lactose/química , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Animais , Aspergillus niger/enzimologia , Glucose/metabolismo , Glucose/química , Catalase/metabolismo , Catalase/química , Membranas Artificiais
11.
Sensors (Basel) ; 24(2)2024 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38276375

RESUMO

Diabetes patients need to monitor blood glucose all year round. In this article, a novel scheme is proposed for blood glucose detection. The proposed sensor is based on a U-shaped microfiber prepared using hydrogen-oxygen flame-heating technology, and then 3-aminopropyltriethoxysilane (APTES) and glucose oxidase (GOD) are successively coated on the surface of the U-shaped microfiber via a coating technique. The glucose reacts with the GOD of the sensor surface to produce gluconic acid, which changes the effective refractive index and then shifts the interference wavelength. The structure and morphology of the sensor were characterized via scanning electron microscope (SEM) and confocal laser microscopy (CLM). The experimental results show that the sensitivity of the sensor is as high as 5.73 nm/(mg/mL). Compared with the glucose sensor composed of the same material, the sensitivity of the sensor increased by 329%. The proposed sensor has a broad application prospect in blood glucose detection of diabetic patients due to the advantages of miniaturization, high sensitivity, and good stability.


Assuntos
Técnicas Biossensoriais , Glicemia , Humanos , Glucose Oxidase/química , Técnicas Biossensoriais/métodos , Glucose/química , Fibras Ópticas
12.
Nano Lett ; 23(14): 6610-6618, 2023 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-37458704

RESUMO

Diabetic ulcers have received much attention in recent years due to their high incidence and mortality, motivating the scientific community to develop various strategies for such chronic disease treatments. However, the therapeutic outcome of these approaches is highly compromised by invasive bacteria and a severe inflammatory microenvironment. To overcome these dilemmas, microenvironment-responsive self-delivery glucose oxidase@manganese sulfide (GOx@MnS) nanoparticles (NPs) are developed by one-step biomineralization. When they encounter the high glucose level in the ulcer site, GOx particles catalyze glucose to decrease the local pH and trigger the steady release of both manganese ions (Mn2+) and hydrogen sulfide (H2S). Mn2+ reacts with hydrogen peroxide to generate hydroxyl radicals for the elimination of bacterial infection; meanwhile, H2S is able to suppress the inflammatory response and accelerate diabetic wound healing through macrophage polarization. The excellent biocompatibility, strong bactericidal activity, and considerable immunomodulatory effect promise GOx@MnS NPs have great therapeutic potential for diabetic wound treatment.


Assuntos
Diabetes Mellitus , Sulfeto de Hidrogênio , Nanopartículas , Humanos , Glucose Oxidase/uso terapêutico , Glucose , Peróxido de Hidrogênio
13.
Angew Chem Int Ed Engl ; 63(8): e202311476, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-37990059

RESUMO

Continuous and non-invasive glucose monitoring and imaging is important for disease diagnosis, treatment, and management. However, glucose monitoring remains a technical challenge owing to the dearth of tissue-transparent glucose sensors. In this study, we present the development of near-infrared fluorescent single-walled carbon nanotube (SWCNT) based nanosensors directly functionalized with glucose oxidase (GOx) capable of immediate and reversible glucose imaging in biological fluids and tissues. We prepared GOx-SWCNT nanosensors by facile sonication of SWCNT with GOx in a manner that-surprisingly-does not compromise the ability of GOx to detect glucose. Importantly, we find by using denatured GOx that the fluorescence modulation of GOx-SWCNT is not associated with the catalytic oxidation of glucose but rather triggered by glucose-GOx binding. Leveraging the unique response mechanism of GOx-SWCNT nanosensors, we developed catalytically inactive apo-GOx-SWCNT that enables both sensitive and reversible glucose imaging, exhibiting a ΔF/F0 of up to 40 % within 1 s of exposure to glucose without consuming the glucose analyte. We finally demonstrate the potential applicability of apo-GOx-SWCNT in biomedical applications by glucose quantification in human plasma and glucose imaging in mouse brain slices.


Assuntos
Técnicas Biossensoriais , Nanotubos de Carbono , Animais , Camundongos , Humanos , Glucose , Glucose Oxidase/metabolismo , Glicemia , Automonitorização da Glicemia , Técnicas Biossensoriais/métodos
14.
Small ; 19(46): e2304058, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37475522

RESUMO

"Warburg Effect" shows that most tumor cells rely on aerobic glycolysis for energy supply, leading to malignant energy deprivation and an "internal alkaline external acid" tumor microenvironment. Destructing the "Warburg Effect" is an effective approach to inhibit tumor progression. Herein, an acidity-responsive nanoreactor (Au@CaP-Flu@HA) is fabricated for toxic acidosis and starvation synergistic therapy. In the nanoreactor, the fluvastatin (Flu) could reduce lactate efflux by inhibiting the lactate-proton transporter (monocarboxylate transporters, MCT4), resulting in intracellular lactate accumulation. Meanwhile, the glucose oxidase-mimic Au-nanocomposite consumes glucose to induce cell starvation accompanied by gluconic acid production, coupling with lactate to exacerbate toxic acidosis. Also, the up-regulated autophagic energy supply of tumor cells under energy deprivation and hypoxia aggravation is blocked by autophagy inhibitor CaP. Cellular dysfunction under pHi acidification and impaired Adenosine Triphosphate (ATP) synthesis under starvation synergistically promote tumor cell apoptosis. Both in vitro and in vivo studies demonstrate that this combinational approach of toxic-acidosis/starvation therapy could effectively destruct the "Warburg Effect" to inhibit tumor growth and anti-metastatic effects.


Assuntos
Acidose , Neoplasias , Humanos , Glicólise , Neoplasias/patologia , Ácido Láctico , Nanotecnologia , Linhagem Celular Tumoral , Microambiente Tumoral
15.
Small ; 19(10): e2206257, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36549673

RESUMO

This work focusses on developing a hybrid enzyme biofuel cell-based self-powered biosensor with appreciable stability and durability using murine leukemia fusion gene fragments (tDNA) as a model analyte. The cell consists of a Ti3 C2 Tx /multiwalled carbon nanotube/gold nanoparticle/glucose oxidase bioanode and a Zn/Co-modified carbon nanotube cathode. The bioanode uniquely exhibits strong electron transfer ability and a high surface area for the loading of 1.14 × 10-9  mol cm-2 glucose oxidase to catalyze glucose oxidation. Meanwhile, the abiotic cathode with a high oxygen reduction reaction activity negates the use of conventional bioenzymes as catalysts, which aids in extending the stability and durability of the sensing system. The biosensor offers a 0.1 fm-1 nm linear range and a detection limit of 0.022 fm tDNA. Additionally, the biosensor demonstrates a reproducibility of ≈4.85% and retains ≈87.42% of the initial maximal power density after a 4-week storage at 4 °C, verifying a significantly improved long-term stability.


Assuntos
Fontes de Energia Bioelétrica , Técnicas Biossensoriais , Nanopartículas Metálicas , Nanotubos de Carbono , Animais , Camundongos , Glucose Oxidase/metabolismo , Biocombustíveis , Ouro , Reprodutibilidade dos Testes , Titânio , Eletrodos , Glucose
16.
Crit Rev Biotechnol ; 43(5): 698-715, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35723581

RESUMO

The regulation and prohibition of antibiotics used as growth promoters (AGP) in the feed field are increasing because they cause antimicrobial resistance and drug residue issues and threaten community health. Recently, glucose oxidase (GOx) has attracted increasing interest in the feed industry as an alternative to antibiotics. GOx specifically catalyzes the production of gluconic acid (GA) and hydrogen peroxide (H2O2) by consuming molecular oxygen, and plays an important role in relieving oxidative stress, preserving health, and promoting animal growth. To expand the application of GOx in the feed field, considerable efforts have been made to mine new genetic resources. Efforts have also been made to heterologously overexpress relevant genes to reduce production costs and to engineer proteins by modifying enzyme properties, both of which are bottleneck problems that limit industrial feed applications. Herein, the: different sources, diverse biochemical properties, distinct structural features, and various strategies of GOx engineering and heterologous overexpression are summarized. The mechanism through which GOx promotes growth in animal production, including the improvement of antioxidant capacity, maintenance of intestinal microbiota homeostasis, and enhancement of gut function, are also systematically addressed. Finally, a new perspective is provided for the future development of GOx applications in the feed field.


Assuntos
Glucose Oxidase , Peróxido de Hidrogênio , Animais , Glucose Oxidase/genética , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo , Antibacterianos , Glucose/metabolismo
17.
Chemistry ; 29(34): e202300454, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37026579

RESUMO

Au nanoparticles (NPs) have been proven to be excellent glucose oxidase (GOx) mimics, which can catalyze the electrons transform pathway from glucose to oxygen. This study confirmed AuNPs can accelerate the reaction between [Ag(NH3 )2 ]+ and glucose under alkaline conditions, which is also known as the Tollens' reaction, and the possible mechanism was proposed. Here, [Ag(NH3 )2 ]+ instead of O2 acted directedly as an electron acceptor during glucose oxidation catalyzed by AuNPs, accompanied by hydrogen transfer. The as-synthesized Ag nanoparticles can also catalyze this process, similar to AuNPs, via a unique cascading catalysis mechanism in the Tollens' reaction. A simple and heatless glucose colorimetric assay can be established based on the plasmonic band of AgNPs with a liner range of 0.6-22.2 µM, and the limit of detection is 0.32 µM.


Assuntos
Glucose Oxidase , Nanopartículas Metálicas , Ouro , Prata , Glucose , Colorimetria , Catálise , Peróxido de Hidrogênio
18.
Anal Biochem ; 675: 115224, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37393976

RESUMO

As a type of nanomaterials with enzyme-mimetic catalytic properties, nanozymes have attracted wide concern in biological detection. H2O2 was the characteristic product of diverse biological reactions, and the quantitative analysis for H2O2 was an important way to detect disease biomarkers, such as acetylcholine, cholesterol, uric acid and glucose. Therefore, there is of great significance for developing a simple and sensitive nanozyme to detect H2O2 and disease biomarkers by combining with corresponding enzyme. In this work, Fe-TCPP MOFs were successfully prepared by the coordination between iron ions and porphyrin ligands (TCPP). In addition, the peroxidase (POD) activity of Fe-TCPP was proved, in detail, Fe-TCPP could catalyze H2O2 to produce ·OH. Herein, glucose oxidase (GOx) was chosen as the model to build cascade reaction by combining Fe-TCPP to detect glucose. The results indicated glucose could be detected by this cascade system selectively and sensitively, and the limit of detection of glucose was achieved to 0.12 µM. Furthermore, a portable hydrogel (Fe-TCPP@GEL) was further established, which encapsulated Fe-TCPP MOFs, GOx and TMB in one system. This functional hydrogel could be applied for colorimetric detection of glucose by coupling with a smartphone easily.


Assuntos
Estruturas Metalorgânicas , Porfirinas , Glucose/análise , Peróxido de Hidrogênio , Colorimetria/métodos , Peroxidases , Biomarcadores , Glucose Oxidase
19.
Anal Biochem ; 667: 115091, 2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-36863551

RESUMO

The study presents a novel electrochemical glucose biosensor based on glucose oxidase (GOx) immobilized on Au@Pd core-shell nanoparticles supported on carboxylated graphene oxide (cGO). The immobilization of GOx was achieved by cross-linking the chitosan biopolymer (CS) including Au@Pd/cGO and glutaraldehyde (GA) on a glassy carbon electrode. The analytical performance of GCE/Au@Pd/cGO-CS/GA/GOx was investigated using amperometry. The biosensor had fast response time (5.2 ± 0.9 s), a satisfactory linear determination range between 2.0 × 10-5 and 4.2 × 10-3 M, and limit of detection of 10.4 µM. The apparent Michaelis-Menten constant (Kapp) was calculated as 3.04 mM. The fabricated biosensor also exhibited good repeatability, reproducibility, and storage stability. No interfering signals from dopamine, uric acid, ascorbic acid, paracetamol, folic acid, mannose, sucrose, and fructose were observed. The large electroactive surface area of carboxylated graphene oxide is a promising candidate for sensor preparation.


Assuntos
Técnicas Biossensoriais , Grafite , Reprodutibilidade dos Testes , Enzimas Imobilizadas , Glucose , Glucose Oxidase , Eletrodos , Técnicas Eletroquímicas
20.
Microb Cell Fact ; 22(1): 38, 2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36841771

RESUMO

Trichoderma reesei (T. reesei) is well-known for its excellent ability to secret a large quantity of cellulase. However, unlike the endogenous proteins, little is known about the molecular mechanisms governing heterologous protein production. Herein, we focused on the integration loci and the secretory pathway, and investigated their combinatorial effects on heterologous gene expression in T. reesei using a glucose oxidase from Aspergillus niger as a model protein. Integration in the cel3c locus was more efficient than the cbh1 locus in expressing the AnGOx by increasing the transcription of AnGOx in the early stage. In addition, we discovered that interruption of the cel3c locus has an additional effect by increasing the expression of the secretory pathway component genes. Accordingly, overexpressing three secretory pathway component genes, that were snc1, sso2, and rho3, increased AnGOx expression in the cbh1 transformant but not in the cel3c transformant.


Assuntos
Celulase , Trichoderma , Aspergillus niger/genética , Proteínas Fúngicas/metabolismo , Glucose Oxidase/genética , Glucose Oxidase/metabolismo , Via Secretória , Trichoderma/metabolismo , Celulase/metabolismo
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