121 results about "Isoelectric point" patented technology

The invention relates generally to compositions and methods for purifying the desired species from a mixture of desired heterodimer and contaminating homodimer immunoglobulin variants by modifying the isoelectric point(s) of the individual chains.

The invention relates to the field of biological medicine preparation, and particularly provides liraglutide precursor peptide tandem recombinant fusion protein, polynucleotide, recombinant expression plasmid, engineered host cell and a method for preparing target polypeptide. The recombinant fusion protein is fusion peptide-target polypeptide-(linker peptide-target polypeptide) n from the N terminal to the C terminal, n is a positive integer from 4 to 6, the fusion peptide is SEQ ID NO.1, the target polypeptide is liraglutide precursor peptide, the linker peptide comprises a spacer peptide and a protease restriction enzyme cutting site, the spacer peptide is SEQ ID NO.2, the isoelectric point of the recombinant fusion protein is 4.6-4.7, and the average hydrophilic value is-0.780--0.765. The proportion of the target polypeptide in the recombinant fusion protein is high, use of solvents under extreme conditions is avoided in the production process, the enzyme digestion efficiency is high, and the product purity and yield are high.

The invention relates to the field of biological medicine preparation, and particularly provides canagliflozin precursor peptide tandem recombinant fusion protein, polynucleotide, recombinant expression plasmid, engineered host cell and a method for preparing target polypeptide. The recombinant fusion protein is a fusion peptide-target polypeptide-(linker peptide-target polypeptide) n from an N terminal to a C terminal, n is a positive integer of 4-6, the fusion peptide is SEQ ID NO.1 or SEQ ID NO.2, the target polypeptide is a canagliptin precursor peptide, the linker peptide comprises a spacer peptide and a protease restriction enzyme cutting site, the spacer peptide is SEQ ID NO.3, the isoelectric point of the recombinant fusion protein is 5.5-6.5, and the average hydrophilic value is-0.85--0.96. The invention creatively provides a method for preparing the canagliflozin precursor peptide by using a gene recombination technology, the proportion of the target polypeptide in the recombinant fusion protein is high, the use of a solvent under extreme conditions is avoided in the production process, the enzyme digestion efficiency is high, and the product purity and yield are high.

The application discloses a biosynthesis method of blue copper peptide, comprising the following steps: synthesizing a recombinant protein according to an amino acid sequence shown in SEQ ID NO. 1, synthesizing a gene coding the recombinant protein, constructing a recombinant plasmid by using the gene, transferring the recombinant plasmid into a host bacterium, carrying out fermentation culture to induce protein expression, separating the protein, carrying out enzyme cutting and purification, and finally carrying out complexing with copper ions to obtain the blue copper peptide. Compared with the prior art, the biosynthesis method of the blue copper peptide has the advantages of low production cost, green environmental protection and high yield by optimizing the design of the fusion protein, and the yield of the final product can be significantly improved, and the fusion protein has better structure and isoelectric point characteristics.

The application provides a fluorine-doped Fe-N-C composite material and a preparation method and application and regeneration thereof, and belongs to the technical field of water pollution. In the application, an iron precursor, a zinc salt, an organic ligand and an organic solvent are mixed to synthesize Fe-doped metal organic framework Fe@ZIF-8 material, and then the Fe@ZIF-8 material is carbonized into Fe-N-C material; then the Fe-N-C material is mixed with a fluorine source and subjected to secondary carbonization to obtain the fluorine-doped Fe-N-C composite material. In the application, fluorine atoms are introduced into the Fe-N-C material to produce axial coordination with Fe of the FeN4 center, the fluorine element with high electronegativity can effectively improve the isoelectric point of the Fe-N-C material, the reaction activity of the material is enhanced, the Fe leaching of the material in the reaction process is inhibited, and the stability of the material is improved. In addition, the prepared fluorine-doped Fe-N-C composite material can be reused through fluorine-doping regeneration, and high reduction activity and stability can be maintained.

The present application relates to the technical field of biological medicine, and particularly relates to a method for extracting and determining selenoprotein from selenium-rich lycoperdon pygmaeum mycelium, wherein the lycoperdon pygmaeum mycelium fermented by a 20L biological culture tank is dried in a vacuum drying box, ground into standard powder through a 100-mesh sieve, 0.5g of the standard powder is weighed, a 0.05mol / L NaOH solution is added, ultrasonic-assisted extraction is performed, then centrifugation is performed at a speed of 3000r / min for 15min, the supernatant is adjusted to an isoelectric point, centrifugation is performed again to obtain a protein precipitate, and finally the protein precipitate is dried in a freeze dryer to obtain a protein sample. The present application is dedicated to using the selenium-rich lycoperdon pygmaeum mycelium as raw material, adopting ultrasonic extraction, optimally optimizing the extraction process of selenoprotein, quantitatively analyzing the selenium content in the protein, detecting the change of the type and quantity of amino acids before and after selenium enrichment through a thin layer chromatography test, and understanding the influence of selenium on the amino acids in the lycoperdon pygmaeum mycelium.

The invention relates to the field of bioengineering, in particular to a construction method and application of an amylopectin ternary nano assembly with a high assembly index. The invention provides a construction method of a ternary nano assembly. The construction method comprises the following steps: S1, extracting amylopectin of bulk crops by adopting an ethanol sedimentation method; s2, extracting endogenous lipids of fruits of completely mature bulk crops by adopting a supercritical carbon dioxide extraction method; s3, extracting endogenous proteins of fruits of immature bulk crops by adopting an isoelectric precipitation method; s4, the amylopectin, the endogenous lipid and the endogenous protein are subjected to a self-assembly reaction, and the ternary nano assembly is obtained. The particle size of the ternary complex can reach nanometer, and the ternary complex is high in CI, high in SDS content, low in multi-stage digestion rate, stable in blood sugar release process and good in chewiness.

The present invention provides a method of modulating a molecular mass of a fusion polypeptide, wherein the fusion polypeptide comprises a target polypeptide fused to a tag suitable for affinity purification or detection of the target polypeptide, wherein the tag comprises at least one constant domain of an immunoglobulin light chain or orthologous polypeptide or fragment thereof and wherein the molecular mass and / or an isoelectric point of the fusion polypeptide is modulated by increasing the molecular mass of the tag via combining the one constant domain of an immunoglobulin light chain or orthologous polypeptide or fragment thereof with one or more further constant domain(s) of an immunoglobulin light chain or orthologous polypeptide(s) or fragment(s) thereof; wherein the constant domain of the immunoglobulin light chain or orthologous polypeptide or fragment thereof of the tag is monomeric; and wherein optionally the target polypeptide is fused to the tag via a first linker. The invention further provides a fusion polypeptide obtained or obtainable by this method. The invention also provides a tag and a fusion polypeptide comprising the tag.

The embodiments described herein relate to free electrophoresis devices or apparatuses on a horizontal plane without other fluid dynamics forces than gravity, and apparatuses and methods for separating and precipitating an analyte of interest from a sample by sequentially adjusting the pH of the solution and focusing and separating the analyte of interest according to its respective isoelectric point. The apparatuses and methods include allowing the sample to be fluid kinetically at rest on a horizontal plane, applying an electric field parallel to the horizontal plane by an anode and a cathode on both sides of the sample, and then moving to focus and precipitate the analyte of interest fractions according to their respective isoelectric points.

The present invention provides a method for producing an inorganic particle-containing slurry, by which the number of coarse particles can be sufficiently reduced. The present invention is a method for producing an inorganic particle-containing slurry, which comprises: a step of preparing an inorganic particle dispersion containing inorganic particles and a dispersing medium, and having a pH less than the isoelectric point of the inorganic particles; and a step of adding an alkaline compound to the inorganic particle dispersion in such a manner that the pH does not reach the isoelectric point of the inorganic particles.

To provide boehmite in which a polymer dispersant is adhered or bonded to a particle surface and which does not exhibit dilatancy and is excellent in dispersibility. To provide a method for producing boehmite by adding a dispersant to a slurry of aluminum hydroxide and water and subjecting the slurry to hydrothermal treatment, by which boehmite not exhibiting dilatancy and excellent in dispersibility can efficiently be produced.SOLUTION: The present invention relates to boehmite in which a polymer dispersing agent is attached or bonded to surfaces of particles of the boehmite, the boehmite having a carbon content of 0.01% by weight to 0.17% by weight, an isoelectric point of pH2. 9 to 6.7, and exhibiting no dilatancy. The present invention relates to a method for producing the boehmite, including subjecting a slurry containing aluminum hydroxide, a polymer dispersant in an amount of 0.03% by weight to less than 1% by weight based on the weight of the aluminum hydroxide, and water to a hydrothermal treatment.SELECTED DRAWING: Figure 1

An antimicrobial peptide against Bacillus cereus, a preparation method therefor and a use thereof. The antimicrobial peptide against bacillus cereus has the general amino acid sequence formula of [KR]GG[KR]XC[FWY]C[KR]X[KR][FWY]C[LIAV]CXG[KR][KR], wherein the antimicrobial peptide XWC26 has a strong antibacterial activity against Bacillus cereus, efficiently inhibiting the spore germination of Bacillus cereus, and effectively controlling Bacillus cereus contamination in food. The antimicrobial peptide against bacillus cereus has the amino acid sequence of KGGKLCWCKNKWCICLGKR, with a molecular weight of 2224.79 Da, an isoelectric point of 9.70, and a net charge of 6. The antimicrobial peptide also has the advantages of high stability, reduced risk of drug resistance induction, high synthesis efficiency, low production costs, etc.

The invention relates to a preparation method of a conductive cellulose nanocrystal composite hydrogel type multifunctional force-electricity sensing material. The coating amount of polyaminophenylboronic acid finally polymerized on cellulose nanocrystal is regulated and controlled by controlling the feeding ratio of a cellulose nanocrystal carrier to an aminophenylboronic acid monomer as well as the feeding ratio of the aminophenylboronic acid monomer to a free radical initiator; and finally, the conductivity and the dispersity of the PAC are controlled. The PAC suspension is subjected to deprotonation regulation and control to avoid gelatin isoelectric points when being compounded with gelatin, so that the interfacial compatibility during compounding is controlled, and the mechanical property and the conductivity of the hydrogel are improved; the sol is subjected to low-temperature cooling and gelatinization to prepare a mechanical-electric dual-function integrated cellulose nanocrystal composite gelatin hydrogel material, and a multifunctional mechanical-electric sensing device is prepared from the cellulose nanocrystal composite gelatin hydrogel; and a new design thought is provided for construction of a high-performance bio-based electro-mechanical hydrogel piezoresistive-piezoelectric dual-sensing wearable device.

This invention provides a colloidal gold labeling method with improved sensitivity, its applications, and products, relating to the field of immunochromatography technology. The colloidal gold labeling method provided by this invention involves mixing a protein to be labeled, treated with a protein activator, with a colloidal gold solution for labeling reaction to obtain a gold-labeled protein. The protein activator includes a nonionic surfactant, a glycoprotectant, and a reducing agent. Through the synergistic effect of these components, the interactions between the gold-labeled conjugates are effectively reduced, preventing aggregation and improving the stability of the gold-labeled conjugates while protecting protein activity. The pH of the colloidal gold solution is 0.3-0.8 lower than the isoelectric point of the protein to be labeled. Under these conditions, the gold-labeled conjugates formed have good stability and high labeling efficiency. This method is simple to operate, the prepared gold-labeled conjugates have high labeling efficiency and good stability, and the prepared reagent kit has high sensitivity and is less prone to missed detections.

Embodiments described herein relate to a device or apparatus for isoelectric aggregation precipitation of proteins in a solution on a horizontal plane, an apparatus and method for separating and precipitating an analyte of interest from a sample by sequentially adjusting the pH of the solution and pooling and separating the analyte of interest according to corresponding isoelectric points of the analyte of interest. The apparatus and method include subjecting a sample to fluid kinematics resting on a horizontal plane, applying an electric field parallel to the horizontal plane through an anode and a cathode on both sides of the sample, and then pooling and precipitating an analyte fraction of interest according to their respective isoelectric point movement.

The invention relates to physically stable compositions in the form of an injectable aqueous solution, having a pH between 6.0 and 8.0, comprising at least: a) a basal insulin having an isoelectric point (pI) between 5.8 and 8.5 and b) a co-polyamino acid bearing carboxylate charges and at least one hydrophobic radical.

Described herein is a bias-free high-throughput and high-yield continuous isoelectric fractionation (CIF) nanocarrier fractionation technique based on distinct isoelectric points. The nanocarrier fractionation platform is enabled by a robust and tunable linear pH profile provided by water-splitting at a bipolar membrane and stabilized by flow without ampholytes.

The application belongs to the field of antibodies, and particularly relates to a CD47-targeting antibody mutant and application thereof, wherein the amino acid sequence of the heavy chain variable region of the CD47-targeting antibody mutant is shown as SEQ ID NO: 3, and the amino acid sequence of the light chain variable region of the CD47-targeting antibody mutant is shown as SEQ ID NO: 4; the application implements multidimensional developability optimization on the light and heavy chain variable regions of the anti-human CD47 antibody through computer-aided molecular design combined with experimental verification, and comprehensively considers parameters such as folding free energy, surface charge distribution, hydrophobic exposure area and local stability, and an optimized mutant is screened; the optimized mutant obtained by the application realizes isoelectric point reduction, hydrophobicity weakening and charge symmetry and hydrophilic exposure improvement under the premise of not reducing affinity, can be used for preparing a drug for treating tumors related to high expression of CD47, and provides a general technical approach for AI-based antibody developability and stability modification.

The application discloses an immunoregulatory peptide BugaCATH and application thereof, and belongs to the field of biomedicine. Buga The CATH is a cyclic polypeptide with a pair of intramolecular disulfide bond composed of a sixth cysteine and a thirteenth cysteine, and has a molecular weight of 3156.67 Dalton and an isoelectric point of 8.76, wherein the amino acid sequence is shown as SEQ ID NO: 2. Buga The gene (GenBank accession: OQ870533) of the CATH precursor is composed of 663 nucleotide sequences, and the nucleotide sequence is shown as SEQ ID NO: 1; wherein the nucleotide at the positions of 322-448 is the immunoregulatory peptide Buga The encoding gene of the CATH. The immunoregulatory peptide Buga The application of the CATH in the preparation of a treatment drug for promoting skin wound repair.

The invention discloses Japanese eel antibacterial peptide Ajaponin and application thereof, the Japanese eel antibacterial peptide Ajaponin is composed of 21 amino acids, the molecular weight is 2693.29 Dalton, the molecular weight contains 7 positively charged amino acid residues, the hydrophobicity is 0.316, the isoelectric point is 11.45, the Japanese eel antibacterial peptide Ajaponin is a novel cationic short peptide, has the advantages of good water solubility, high antibacterial activity, low toxicity and the like, is composed of limited amino acid residues, and can be used as a novel cationic short peptide. The structure is compact, synthesis and purification are easy, and large-scale production and application are facilitated; and the amino acid residues containing a plurality of positive charges are beneficial to interaction with negative charges of bacterial cell membranes and destroy the integrity of the membranes, so that the effects of rapidly inhibiting and killing bacteria are achieved.

The invention belongs to the field of small molecule polypeptides, and particularly relates to a scallop polypeptide with a protein aggregation resisting function and application of the scallop polypeptide. The pure natural scallop polypeptide is extracted, separated and identified by taking scallops as raw materials through the steps of enzymolysis separation, ultrafiltration purification, LC-MS / MS identification and the like, the amino acid sequence of the scallop polypeptide is TMYWTDVSNGQIHR, the molecular formula is C74H110N22O23S, the average relative molecular mass is about 1707.88 Da, the theoretical isoelectric point is pH = 6.41, and the scallop polypeptide is hydrophilic polypeptide. The scallop polypeptide has the functions of oxidation resistance, protein aggregation resistance and neuroprotection, can be further applied to development of products such as food, medicines and health care products, and has a wide application prospect.

The invention claimed herein relates to a dielectric polishing composition and a method thereof. The invention claimed herein particularly relates to a composition comprising: (A) surface-modified colloidal silica particles comprising negatively charged groups on the surface of the particles, wherein the surface-modified colloidal silica particles have a negative charge, a particle size of 60 nm to 200 nm, and a zeta potential of < -35 mV at a pH in the range of > 2.0 to < 6.0; (B) at least one corrosion inhibitor selected from at least one guanidine derivative; (C) at least one iron (III) oxidizing agent; (D) at least one buffering agent selected from at least one basic amino acid having an isoelectric point (pi) of > 6.5; (E) at least one stabilizer; and (F) an aqueous medium, wherein the pH of the composition is in the range of > 2.0 to < 4.3, and wherein the composition has a polyacrylamide content of < 1 ppm.

Provided herein are methods for producing a mung bean protein isolate having high functionality for a broad range of food applications. In some embodiments, the methods for producing the isolate comprise one or more steps selected from: (a) extracting one or more mung bean proteins from a mung bean protein source in an aqueous solution, for example, at a pH between about 6.5-10.0; (b) purifying protein from the extract using at least one of two methods: (i) precipitating protein from the extract at a pH near the isoelectric point of a globulin-rich fraction, for example a pH between about 5.0-6.0; and / or (ii) fractionating and concentrating protein from the extract using filtration such as microfiltration, ultrafiltration or ion-exchange chromatography; and (c) recovering purified protein isolate.

A composition, comprising: a bioactive glass, comprising: 10-60 wt.% SiO2; 0-15 wt.% ZrO2; 10-60 wt.% CaO; and 1-30 wt.% P2O5; based on total weight of the bioactive glass; at least one first amino acid comprising a side chain, the side chain having a functional group having a pKa of 7 or less; and at least one second amino acid different from the first amino acid, the at least one second amino acid having an isoelectric point of 5-8; wherein the composition has a pH of 5-9.

The application discloses a preparation method of fluorine-containing Fe3O4 nano-assemblies and application of the fluorine-containing Fe3O4 nano-assemblies in intracellular protein delivery, and the preparation method comprises the following steps: preparing Fe3O4 nanoparticles and small-molecule ligands containing fluorine alkyl chains respectively, and the two are combined through ligand exchange reaction to form fluorine-containing Fe3O4 nanoparticles; the fluorine-containing Fe3O4 nanoparticles can be self-assembled with proteins to form stable complexes through the hydrophobic effect and electrostatic effect of the fluorine alkyl chains. The fluorine-containing Fe3O4 assemblies provided by the application have universality as intracellular protein delivery carriers, can effectively deliver proteins with different isoelectric points and molecular weights to tumor cells, do not affect the biological activity of the cargo proteins, have small toxicity to cells, and have good biocompatibility. The protein delivery efficiency of the assemblies is further improved under the guidance of an external magnetic field, so that the killing effect of therapeutic proteins on tumor cells is enhanced, and the assemblies have application potential in the field of tumor treatment.

The application belongs to the technical field of saponification grease refining extraction, and discloses a kind of oil and fat by-products in cowhide pretreatment waste liquid and extraction method and application.The application uses the combined waste liquid generated in the process of collagen peptide production as raw material, adopts non-isoelectric point salt-free gentle flocculation demulsification process, accurately controls the system pH to 4.6~5.0, can completely remove macromolecular impurities such as impure protein, dander gum, etc., while controllably retaining trace amounts of small molecule denatured collagen polypeptide, then through hydration degumming, alkali refining deacidification, water washing and drying, decolorization and deodorization processes to obtain finished oil and fat.The core physicochemical indexes of the oil and fat obtained by the application meet the standard of soap grease, and the saponification reaction efficiency, soap texture flexibility and foam performance are significantly better than those of traditional completely deproteinized refined beef tallow, realizing high-purity refining and performance synergistic effect of waste liquid oil and fat, high added value of by-products, and process adaptation to industrial large-scale production.

The application discloses a plasma modified polyurethane medical dressing and a preparation method and application thereof, and relates to the technical field of medical dressings. The polyurethane sponge is cleaned and dried, and then is treated by using a plasma technology in an oxygen atmosphere to obtain treated polyurethane sponge; then, recombinant collagen with a HIS tag is prepared into a recombinant collagen solution; then, metal ions with antibacterial effects are added into the solution; the treated polyurethane sponge in step S1 is contacted with the recombinant collagen solution; finally, the modified polyurethane medical dressing is immersed into a high-molecular solution with a low isoelectric point and a negative charge under a neutral condition, and the medical dressing is obtained after drying and washing after immersion. The preparation method avoids the use of chemical cross-linking agents, ingeniously uses the tag of the recombinant collagen, simplifies an antibacterial substance loading process, and enables the antibacterial agent not to be excessive, so that the antibacterial agent can be used for a long time at a wound and can be safely applied to the fields of negative pressure drainage and wound care.

The invention discloses a method for predicting the rejection rate of a nanofiltration membrane to micropollutants and application of the method, and belongs to the technical field of membrane separation.The method combines various basic physicochemical principles to construct a set of physical model for electrostatic interaction between the nanofiltration membrane surface and the micropollutants, the model can test the pH of feed liquid through a membrane surface isoelectric point IEP, and the rejection rate of the nanofiltration membrane to the micropollutants can be predicted. According to the method, the electrostatic interaction force parameter between the micro-pollutants and the nanofiltration membrane is accurately calculated according to the experimental parameters such as the micro-pollutant pKa and the micro-pollutant pKa which are easy to obtain, and the rejection rate of the nanofiltration membrane to the micro-pollutants can be further calculated, so that the surface modification direction of the nanofiltration membrane is guided. The method can be used for guiding the surface modification direction of the nanofiltration membrane, and has a good application prospect in the aspect of membrane separation performance optimization, especially in the aspect of high-performance nanofiltration membrane customization for specific micropollutant removal.

The present disclosure discusses a method of separating and / or purifying acidic peptides by the use of a mobile phase having a pH greater than or about equal to the isoelectric point of one or more of the metal oxides in the flow path.

Provided herein are pharmaceutical compositions and formulations of a conjugate comprising a first protein, such as an anti-VEGF antibody, conjugated to a phosphorylcholine-containing polymer, and a second protein not conjugated to the phosphorylcholine-containing polymer. The second protein may be the same as the first protein or may be different from the first protein. In some embodiments, the pH of the formulation is different from the isoelectric point (pI) of the second protein to prevent or reduce the turbidity of the formulation. Also provided are methods of making the formulations, methods of use thereof, and kits having pre-filled syringes containing the formulations.