13 results about "Lactate oxidase" patented technology

Disclosed herein is directed to a lactate oxidase variant that exhibits reduced affinity to lactate as compared to a wild-type lactate oxidase. The lactate oxidase variant has one or more amino acid substitutions occurring at positions 95, 96, and / or 175 of the wild-type amino acid sequence. Also disclosed herein is a method for detecting and quantifying lactate in various liquid samples by using the present lactate oxidase variant. The method mainly includes steps of contacting the liquid sample with said lactate oxidase variant; measuring a current generated by the reaction between the lactate oxidase variant and the lactate in the liquid sample; and determining the concentration of lactate in the liquid sample by interpolating or extrapolating the current with that of a control sample having a known concentration of lactate.

The invention relates to the technical field of nano biological medicines, and discloses a photo-thermal-enzyme catalysis nano-particle as well as a preparation method and application thereof. The photo-thermal-enzyme catalysis nano-particles are constructed by crosslinking water-soluble self-doped polyaniline nano-particles, human serum albumin, lactate oxidase and collagenase through a thioacetal linker capable of being split by active oxygen. Collagenase and lactate oxidase (LOx) are integrated into the same nanoparticle system through a thioacetal (TK) linker, the TK linker is split under the action of tumor microenvironment active oxygen (ROS) and H2O2 generated by catalysis of the LOx, the activity of the two enzymes is synchronously activated, a collagen matrix (physical barrier) is degraded, lactic acid (chemical barrier) is removed, the tumor microenvironment is efficiently remodeled, and the tumor microenvironment can be effectively inhibited. The problems that the regulation effect of a single barrier is limited, and the tumor microenvironment is difficult to improve are solved.

This invention provides a method for preparing and applying a nanosystem for regulating the osteogenic microenvironment. The nanosystem comprises catalase, lactate oxidase, and a strontium-containing mineralized nanolayer. Experiments demonstrate that this nanosystem can effectively treat bone aging-related diseases, and that catalase and lactate oxidase have a synergistic effect. This invention provides a novel treatment strategy for bone aging-related diseases and has broad prospects for clinical translation.

The invention relates to the technical field of novel biological materials, and particularly discloses an active oxygen and lactic acid dual-driven chemotactic nano motor and a preparation method thereof. Comprising lactate oxidase and selenium nanoparticles, the selenium nano-particles are formed by ascorbic acid and sodium selenite through a chemical reduction method, and the surfaces of the selenium nano-particles are modified with polysaccharide for stabilizing the selenium nano-particles; the lactate oxidase is loaded on the selenium nano-particles to form the nano-motor. Lactic acid is specifically consumed by loading lactic acid oxidase on the surface of the selenium nano-motor, due to high selectivity, the nano-motor can perform directional chemotactic movement towards a lactic acid high expression site, and the excellent oxidation resistance of selenium nano-particles can remove active oxygen and avoid oxidative stress damage, so that the lactic acid and the active oxygen are consumed at the same time.

The application relates to the technical field of biosensors, and discloses a metal nucleic acid framework nanocascade enzyme as well as a preparation method and application thereof. The preparation method of the nanocascade enzyme is as follows: nucleotide sequences shown in SEQ ID NO. 1-10 are mixed in an equimolar ratio, annealing reaction is carried out to obtain a metal template DNA nanosheet; the DNA nanosheet is reacted with a metal precursor to obtain the metal nucleic acid framework nanocascade enzyme. The metal nucleic acid framework nanocascade enzyme DNS-Fe has catalase activity, after corresponding aptamers are added, the DNS-Fe can accurately recognize target objects in various interferents, and the accuracy is high; DNS-Pt / Fe has lactic acid oxidase, glucose oxidase and sarcosine oxidase activity; DNS-Ag / Fe has uric acid oxidase activity; the combination of the DNS-Fe and the DNS-Ag / Fe can realize cascade action, replace natural catalase to catalyze hydrogen peroxide to generate free radicals, and the free radicals are reacted with chromogenic substances to generate a color reaction, and the results are easy to observe.

This invention discloses albumin nanoparticles co-loaded with flavin and lactate oxidase, their preparation method, and applications. Using human serum albumin as a carrier, flavin and lactate oxidase are simultaneously encapsulated at a mass ratio of 10:1, with a particle size of 150-180 nm and a polydispersity index of less than 0.2. This invention exerts its anti-hepatocellular carcinoma effect through mechanisms such as reducing lactate levels in the tumor microenvironment, inducing an increase in reactive oxygen species, inhibiting cGAS protein lactation modification, and activating the cGAS-STING signaling pathway. The nanoparticles exhibit high encapsulation efficiency and good stability. The flavin loaded on these nanoparticles can significantly reduce the reduction of pyruvate to lactate by inhibiting lactate dehydrogenase; simultaneously, the lactate oxidase loaded on these nanoparticles catalyzes the dehydrogenation of lactate to pyruvate. In other words, these nanoparticles synergistically regulate lactate metabolism through a two-way regulatory strategy of "reducing source and increasing sink"—"inhibiting lactate production" and "promoting lactate clearance"—significantly enhancing in vitro and in vivo anti-tumor effects, and demonstrating high biosafety.

Disclosed herein is directed to a lactate oxidase variant that exhibits reduced affinity to lactate as compared to a wild-type lactate oxidase. The lactate oxidase variant has one or more amino acid substitutions occurring at positions 95, 96, and / or 175 of the wild-type amino acid sequence. Also disclosed herein is a method for detecting and quantifying lactate in various liquid samples by using the present lactate oxidase variant. The method mainly includes steps of contacting the liquid sample with said lactate oxidase variant; measuring a current generated by the reaction between the lactate oxidase variant and the lactate in the liquid sample; and determining the concentration of lactate in the liquid sample by interpolating or extrapolating the current with that of a control sample having a known concentration of lactate.

The invention develops a dual-mode optical sensor based on CuO2 nanodots. The dual-mode optical sensor is mainly applied to detection and research of a Warburg effect of gastric cancer. The CuO2 nanodots can catalyze the reaction of o-phenylenediamine (OPD) and hydrogen peroxide (H2O2), so that the color of the solution is changed from colorless to yellow along with the increase of absorbance and fluorescence intensity. Based on the reaction, a dual-mode sensor is designed, and the activity of lactic acid and lactate oxidase is synchronously detected through colorimetry and fluorescence. In the process of catalyzing lactic acid to generate H2O2 by lactic acid oxidase, the generated H2O2 promotes the color of a solution to change remarkably, so that the sensitive detection of the activity of lactic acid and oxidase thereof is indirectly realized. As the Warburg effect of the gastric cancer causes rise of the lactic acid level, the sensor can effectively associate the lactic acid level with the metabolic characteristics of the gastric cancer. In addition, in combination with an RGB colorimetric analysis technology, a smart phone is used for capturing color changes and carrying out image quantitative analysis, a portable, low-cost and high-sensitivity detection system is formed, and the application blank of the CuO2 nanodots in the field is filled up.

The invention discloses a recombinant engineering bacterium for producing recombinant lactate oxidase as well as a construction method and application of the recombinant engineering bacterium, and the construction method comprises the following steps: (1) introducing an HsoLOX gene for coding lactate oxidase into an expression plasmid to construct a recombinant expression vector containing the HsoLOX gene; the nucleotide sequence of the HsoLOX gene is as shown in SEQ ID NO.1 or a sequence of which the homology with the sequence as shown in SEQ ID NO.1 is greater than 90%; and (2) transforming the recombinant expression vector into host bacteria, screening positive clones by taking KanR as a screening marker, and culturing to obtain recombinant engineering bacteria. When the engineering strain is subjected to high-density fermentation for 46 hours, the relative enzyme activity of thalli is 1773 U / g, and the thalli density of a fermentation tank is 262.5 g / L. The invention further provides application of the recombinant lactate oxidase or the whole-cell catalyst and catalase in catalyzing L-sodium lactate together to generate sodium pyruvate, and the conversion rate can reach 99.5%. The operation method is simple and safe, low in production cost, mild in preparation condition, green and pollution-free, and has high economic value and social benefit.

The invention belongs to the technical field of biosensor preparation, and relates to a preparation method of a lactic acid and alpha fetoprotein detection biosensor. The preparation method comprises the following steps: adding single-layer graphene oxide into N, N-dimethylformamide, uniformly mixing, adding polyacrylonitrile, uniformly mixing, and adding dopamine hydrochloride to obtain a spinning solution; and after spinning with the spinning solution, drying in a vacuum drying oven, and then fixing on a gold electrode to obtain an electrode P. And uniformly mixing lactate oxidase and chitosan, dropwise adding the mixture to the surface of the electrode P, dropwise adding an antibody solution after drying, and performing secondary drying to obtain the sensing electrode. The nanofiber membrane with proper pore diameter and fiber diameter is regulated and controlled, is used for preparing a sensor for simultaneously detecting lactic acid and alpha fetoprotein, and has higher performance in detection of a real sample. The detection range of lactic acid and alpha fetoprotein is wide, the preparation process is simple, the cost is low, and the method can be used for large-scale production.

The invention relates to the technical field of biosensors, and discloses a metal nucleic acid framework nano cascade enzyme as well as a preparation method and application thereof. The preparation method of the nano cascade enzyme comprises the following steps: mixing nucleotide sequences as shown in SEQ ID NO.1-10 according to an equal molar ratio, and carrying out annealing reaction to obtain a DNA nanosheet of a metal template; and reacting the DNA nanosheet with a metal precursor to obtain the metal nucleic acid framework nano cascade enzyme. The metal nucleic acid framework nano cascade enzyme DNS-Fe has catalase activity, and after a corresponding aptamer is added, a target object can be accurately recognized in a plurality of interferents, and the accuracy is high; dNS-Pt / Fe has the activity of lactate oxidase, glucose oxidase and sarcosine oxidase, and DNS-Ag / Fe has the activity of urate oxidase, so that the cascade action can be realized by combining the DNS-Pt / Fe with the DNS-Fe, and the DNS-Ag / Fe replaces natural catalase to catalyze hydrogen peroxide to generate free radicals to be subjected to chromogenic reaction with a chromogenic substance, and the result is easy to observe.

Disclosed herein is a printable liquid lactate sensor composition including silk fibroin in an amount by weight of between 0.1% and 30%, a lactate oxidase that is activated by lactate to produce hydrogen peroxide, a peroxidase that is activated by the hydrogen peroxide, and a chromogenic substrate that changes color upon activation of the peroxidase. Wearable sensors including the printable liquid lactate sensor composition are disclosed herein.