79 results about "Enzyme kinetics" patented technology

Compositions and methods for conferring herbicide resistance or tolerance to bacteria, plants, plant cells, tissues and seeds are provided. Compositions include polynucleotides encoding herbicide resistance or tolerance polypeptides, vectors comprising those polynucleotides, and host cells comprising the vectors. The nucleotide sequences of the invention can be used in DNA constructs or expression cassettes for transformation and expression in organisms, including microorganisms and plants. Compositions also comprise transformed bacteria, plants, plant cells, tissues, and seeds. In particular, isolated polynucleotides encoding glyphosate resistance or tolerance polypeptides are provided. Additionally, amino acid sequences corresponding to the polynucleotides are encompassed. In particular, the present invention provides for isolated polynucleotides comprising nucleotide sequences encoding the amino acid sequence shown in SEQ ID NO:2, 4, or 6, or the nucleotide sequence set forth in SEQ ID NO:1, 3, or 5. The present invention additionally provides a method to measure enzyme kinetic activity using fluorogenic substrates.

The invention provides a semi-contact under-oil continuous droplet sample applying and liquid adding method, which is suitable for sequentially operating a droplet array system. According to the method, the distance between the pointed end of a capillary tube sample applying needle and the lower surface of a micro-hole (or a generated droplet) is controlled accurately, and the affinity or interface tension interaction between the droplet and the surface (or the generated droplet) is utilized, so that rapid and reliable continuous droplet sample applying or continuous liquid adding is realized, and the problem of cross infection during sample applying is solved effectively. The method is suitable for biochemical analysis screening researches such as high-flux medicament screening, protein crystallization condition screening, enzyme kinetics research and drug toxicity determination.

A method and a product for cleaning and/or whitening of teeth. Natural human cysteine proteinases are employed for cleaning and whitening purposes and this activity can be blocked by natural cysteine protease inhibitors, which are released secondarily from the product at a later stage. The use of natural cysteine proteinases and their inhibitors provides the advantage that they are man's own proteins, and therefore the risk of allegorization is minimized. In addition, their enzyme kinetics are will known.

The invention discloses a rapid screening method for comprehensively evaluating the in-vitro inhibitory effect of nine human liver CYP450 metabolic enzymes by utilizing 14 probe substrates and 16 probe reaction. The invention mainly relates to a method for monitoring metabolic activity variation of 9 human liver CYP450 enzymes and rapidly and comprehensively evaluating an inhibitory effect of a tested compound on the metabolic enzyme by adopting an in-vitro mixed probe incubation method and LC/MS/MS. According to the method, the exclusiveness and diversity of the probe substrate, interaction of the probe substrates, influence of different inoculation conditions (by charging organic solvent, buffer solution and BSA) in a warm inoculation system and the enzyme kinetics characteristics of 16 probe reactions under the selected inoculation condition are comprehensively considered, a brand new in-vitro system is established by integrating high-sensitive and high-selective LC-MS/MS technology, so that the inhibitory effect of the tested compounds on the nine human liver main metabolic enzymes can be more accurately and comprehensively predicted in the high-throughput screening of the novel drug development, and the predictability on the interaction of the later metabolism can be improved.

The invention discloses a gradient micro-droplet array forming method based on sequential injection and microfluidic technology. The gradient micro-droplet array forming method comprises following steps: step 1, one of a diluent and a sample I is taken using a capillary tube; step 2, the other one of the diluent and the sample I is taken using the capillary tube, and direct contact of the diluent with the sample I is ensured so as to form a sample zone belt with axial concentration gradient; and step 3, the sample zone belt is injected into certain areas of a microporous array chip via the capillary tube so as to obtain sample droplet array with different concentration on the microporous array chip. Advantages of the gradient micro-droplet array forming method are that: concentration gradient generation throughput is high, concentration information is abundant, automatic degree is high; sample consumption is low, and devices and principles are simple. The gradient micro-droplet array forming method can be used for biochemical analysis and screening such as high throughput drug screening, compound toxicity determination, protein crystallization condition screening, catalyst screening, and enzyme dynamic analysis.

The present invention discloses one kind of P450BM-3Asp168His variant gene capable of catalyzing indole to generate indigo blue, and the gene is obtained by means of saturated mutation and directional evolution technology mediated random mutation and screening. The P450BM-3Asp168His variant gene has base sequence as shown in SEQ ID No. 1 of the sequence list, and the aspartic acid codon in the 168-th site of the original P450BM-3(F87V/A74G/L188Q) gene mutated into histidine codon. The enzymic kinetic curve measurement shows that the variant enzyme the obtained variant gene expresses has catalysis efficiency obviously higher than that in available technology. The present invention provides new practical enzyme for the biological synthesis of dye indigo blue and wide application foreground for the biological production of dye indigo blue.

The invention relates to a developing-process fungus 1,3-beta-D-glucan detection kit for human body fluid. The developing-process fungus 1,3-beta-D-glucan detection kit comprises a reaction main agent, a main agent compound solution, a sample treatment solution, heat-source-free water, a standard product and a quality control product, wherein the reaction main agent takes horseshoe crab blood cells as a main raw material and contains G factors, coagulase, coagulase zymogen and a polypeptide developing substrate; the polypeptide developing substrate is synthesized tripeptide or tetrapeptide with a Gly-Arg tail end connected with a PNA; the polypeptide developing substrate is subjected to enzyme digestion by adopting the coagulase; after the free paranitroaniline (PNA) is generated, a microplate reader is used for directly detecting so that a detection route is shortened and the cost is reduced; the microplate reader is used for carrying out a velocity-method enzyme kinetics detection method so that the sensitivity is relatively high when being compared with a nephelometry detection method; and the reaction main agent is not easily interfered by protein in a body fluid sample and medicines to generate non-specific turbidity, so that the probability of a false positive detection result is reduced and the detection accuracy is relatively high.

The invention discloses a gracilaria lemaneiformis antihypertensive peptide and application thereof to preparing antihypertensive drugs and healthcare products. Gracilaria lemaneiformis antihypertensive peptide extract is obtained through enzymolysis and then further separated and purified to obtain the gracilaria lemaneiformis antihypertensive peptide with a specific sequence; the amino acid sequence of the gracilaria lemaneiformis antihypertensive peptide is Phe Gln-Ile-Asn-[Met(O)]-Cys-Ile-Leu-Arg(FQIN[M(O)]CILR), and the molecular weight of the gracilaria lemaneiformis antihypertensive peptide acquired through mass spectrum identification is 1153.43Da. The selected gracilaria lemaneiformis antihypertensive peptide is significant in activity on angiotensin converting enzyme inhibition and can in vitro express temperature, pH, gestro-intestinal digestion and angiotensin converting enzyme (ACE) degradation stability. enzyme kinetics survey shows that the gracilaria lemaneiformis antihypertensive peptide is an ACE non-competitive inhibitor and can achieve good antihypertensive effects in vitro and in vivo of spontaneously hypertensive rats (SHRs), thereby being applicable to hypertensive treatment-related healthcare products and drugs.

The invention relates to an improved body fluid color-developing fungi 1,3-beta-D-glucan detection kit, which comprises a reaction main-agent, a main agent combination solution, a sample treatment fluid, sterile water, a standard substance and a quality control material. With Tachypleus tridentatus Leach or Limulus polyphemus Linnaeus hemocyte lysate as a main raw material, the reaction main-agent contains G factor, B factor, C factor, clottable protein and a polypeptide chromogenic substrate. By a new preparation process, the reaction main-agent has characteristics of high stability and small intra-assay and inter-assay difference. The main agent combination solution adopts a new formula. After the main agent combination solution is mixed with the reaction main-agent, Tachypleus Amebocyte Lysate endotoxin reaction branch can be effectively shielded. According to the kit, rate-method enzyme kinetics detection is carried out by ELIASA. The detection speed is fast, and anti-interference performance is strong. In addition, the preparation technology is simple, and the product has stronger stability and higher specificity and sensitivity.

The present disclosure provides systems for the rapid and sensitive detection of organisms and molecules in samples. Reactants that produce Raman-active products are used in combination with Raman light scattering. Such compounds may comprise phosphates permitting the detection of phosphatases. The present disclosure can also be used to measure enzyme-kinetics.

The invention relates to the technical field of freshness preservation, in particular to a fruit and vegetable respiration rate model. A fruit and vegetable respiration rate modeling method comprises the following steps of: firstly, establishing a model that a respiration rate changes along with storage time: r=K1{1-K2exp(-kdt)}, in the formula, K1=ks/kd*k and K2=1-kd/ks[E]0; secondly, on the basis of the established model that the respiration rate changes along with storage time, establishing a respiration rate model which contains a storage temperature and a storage time factor: r=K3{1-K2exp(-kdt)}, in the formula, K3=ks/kd*Aexp(-Ea/RT); and finally, on the basis of the established respiration rate model which contains the storage temperature and the storage time factor, establishing the respiration rate model which contains a gas volume fraction and the storage time factor: r=K4{1-K2exp(-kdt)}, in the formula, K4=ksktheta/kd*ayO/(1+ayO+aiyOyC). Due to the adoption of the technical scheme, a mathematical model about the respiration rate of fruit and vegetable main bodies is established based on an enzyme kinetic theory to lay a theoretical foundation for the predication of the respiration rate of the fruit and vegetable main bodies in an air conditioned storage period and the analysis of storage quality.

The present invention relates to modified ADAMTS4 proteins having improved stability comparing to the corresponding native, unmodified proteins. The modified ADAMTS4 proteins can be expressed and isolated in large quantities, thus allowing further characterization of the proteins, such as crystallographic and enzyme kinetic studies. The purified, stable proteins would also facilitate the production of anti-ADAMTS antibodies and the development of inhibitors to ADAMTS enzymes.

The invention discloses a DNA sequence of a polypeptide chain with 3 alpha-HSD (3 alpha-hydroxysteroid dehydrogenase) activity. The DNA sequence comprises a complementary chain sequence. The DNA sequence is characterized in that an expression product of the DNA sequence has 3 alpha-hydroxysteroid dehydrogenase activity and is a novel Pseudomonas aeruginosa 3 alpha-hydroxysteroid dehydrogenase. The DNA sequence comprises the following contents: a pseudomonas aeruginosa 3 alpha-hydroxysteriod dehydrogenase gene sequence obtained by utilizing bioinformatics analysis, a recombinant expression vector which contains the pseudomonas aeruginosa 3 alpha-hydroxysteroid dehydrogenase gene sequence, a genetically engineered bacterium which expresses the 3 alpha-hydroxysteroid dehydrogenase 3-hsdA and an enzyme kinetics parameter of the 3 alpha-hydroxysteroid dehydrogenase.

The invention belongs to the technical fields of biological analysis and detection and discloses a nano-sensor for detecting O-acetylglucosamine transferase based on a single quantum dot and a detection method of the nano-sensor. The nano-sensor comprises a cyanine 5/biotin modified peptide chain, non-radioactive uridine-acetylglucosamine and the quantum dot coated with streptavidin, wherein a cyanine 5/biotin modified peptide chain is Biotin-Ser-Thr-Pro-Val-Ser-Arg-Ala-Asn-Met-Lys-Cy5. The detection method of the nano-sensor is very simple, enzyme purification is not required, a radioactive isotope labeled sugar donor, a specific antibody and a fluorescence UDP-GlcNAc analogue do not need to be synthesized, the detection limit can be decreased to 3.47*10<-13> mol/L, and the sensitivity isvery high. The nano-sensor can be further applied to the measurement of enzyme kinetics parameters, the screening of an OGT inhibitor and the quantitative determination of OGT activity of cells.

The invention relates to whole blood urea biosensing test paper. The whole blood urea biosensing test paper comprises a substrate, wherein a work electrode, a reference electrode and connecting wires matched with the work electrode and the reference electrode are printed on the substrate; one end of the substrate is printed with an output terminal of the connecting wire to be connected with a test instrument; and reaction layers capable of reacting with urea are printed on the work electrode and the reference electrode. When the whole blood urea biosensing test paper is adopted for testing blood urea, compared with the enzyme kinetics colorimetry method requiring for a semi-automatic or full-automatic instrument in the prior art, testing is more convenient and quick, so that the blood urea index can be more widely applied to sports monitoring or medical analysis, and a simple and quick test method is provided for general people.

The invention provides a method for separating and purifying inclusion body-type HIV-1 (human immunodeficiency virus-1) protease from a prokaryotic system. In the method, a low-concentration detergent and ultrasonic disruption are combined to separate impurity protein from target protein, and an Amicon stirring type ultrafiltration device is used in an operation process, so that the purifying time of the inclusion body protein is effectively shortened. Moreover, the protein renaturation in the method is implemented by dialysis renaturation, the dialysis process is mild, and the activity and purity of the renatured protease are relatively high. The protein crystallization growth and enzyme kinetics measurement can be performed through simple ultrafiltration concentration, and the method is applied to the study of crystallography and enzymology.

The invention relates to the nano-biotechnology field, and provides a method for detecting enzyme kinetics in a capillary. The method is characterized in that the method comprises the following steps: firstly, quantum dots and polypeptides with fluorescent labels are mixed and reacted outside a capillary, and a quantum dot biological probe is obtained; secondly, fluorescence capillary electrophoresis detection is carried out, namely, enzymes and quantum dot biological probes interact with each other in a capillary, a relation of a ratio of peak value areas of an acceptor detection channel and a donor detection channel and reaction time is determined through fluorescence detection, and a peak area ratio-time standard curve is plotted. The beneficial effects of the method are as follows: operation is simple, the repeatability is high, and applications of quantum dot probes in the bioanalysis field are developed further.

The invention discloses a method for quantifying the tissue culture seedling nitrate utilization efficiency. Clone tissue culture seedlings of inspected plants are obtained through tissue culture; the clone tissue culture seedlings are inoculated onto culture media with different nitrate concentrations respectively for culture; stable nitrogen isotope values of nitrate drugs and tissue culture seedling blades are determined; the tissue culture seedling isotope assimilation ratio under all nitric acid concentration gradients is worked out; a relational model of the tissue culture seedling isotope assimilation ratio and the nitrate concentrations is established according to a michaelis-menten equation of the enzyme kinetics; the model is subjected to derivation, and a tissue culture seedling nitrate utilization efficiency equation is obtained; according to the tissue culture seedling nitrate utilization efficiency equation, the tissue culture seedling nitrate utilization efficiency and the maximum utilization efficiency of nitrate are determined. According to the method, few materials and steps are needed, the calculation method is simple, and online dynamic monitoring can be conducted; the monitoring result can be the supply quantity for effectively managing the culture medium nitrate.