433 results about "Solid-phase synthesis" patented technology

The invention discloses a scorpion anti-inflammatory polypeptide as well as a screening method and application thereof, and belongs to the technical field of traditional Chinese medicinal material polypeptides. The scorpion anti-inflammatory polypeptide is one of G4, G5 and G17. The method comprises the following steps: detecting a scorpion buthus martensii polypeptide extract through nanoElute 2 nanoliter liquid phase separation, timsTOFPro2 mass spectrometry and BPS Novor search analysis, screening a scorpion buthus martensii polypeptide, and further synthesizing the screened candidate polypeptide by adopting a solid-phase synthesis method; the effect of the synthesized candidate polypeptide on inhibiting microglial cell inflammation is evaluated through a qPCR method, and then the scorpion buthus martensii anti-inflammatory polypeptide is screened out. The Buthus martensii Karsch anti-inflammatory polypeptides G4, G5 and G17 screened by the method, especially G5, can significantly inhibit microglial cell inflammation and present concentration dependence, a theoretical basis is provided for medicinal development of Buthus martensii Karsch polypeptides, and a potential anti-neuroinflammation mechanism of the Buthus martensii Karsch polypeptides is disclosed.

The invention discloses a split intein and application thereof, the split intein comprises two independent peptide fragments: (a) an N-terminal fragment, the amino acid sequence of which is as shown in SEQ ID NO.1; (b) a C-terminal fragment or a variant thereof, the amino acid sequence of the C-terminal fragment is as shown in SEQ ID NO.2, and the amino acid sequence of the variant is as shown in SEQ ID NO.3 or SEQ ID NO.4. The split intein has splicing activity and excellent splicing rate, the application of the split intein can be widened, the number of amino acids of the C-terminal fragment or the variant thereof is small, and the split intein has remarkable advantages in protein purification, solid-phase synthesis and the like.

According to the portable solid-phase synthesis reaction device, in the portable solid-phase synthesis reaction device, a support module comprises a synchronous belt lead screw nut; the motor driving module is installed on one side of the upper end edge of the support module to serve as a power source component for adjusting the size of the composite column cavity, the motor driving module comprises a stepping motor and a synchronous wheel, the synchronous wheel is installed on an output shaft of the stepping motor, and the synchronous belt is arranged on the synchronous wheel and the synchronous belt lead screw nut in a sleeving mode; the lead screw lifting module is installed on the column top support to serve as an execution component for adjusting the size of the composite column cavity and comprises a transmission lead screw, a piston unit is installed at the lower end of the transmission lead screw, and the transmission lead screw is in threaded connection with a synchronous belt lead screw nut. The synthesis column body module is mounted in the middle between a column top support and a bottom plate of the support module to serve as a synthesis carrier to be filled and a solid-phase synthesis reaction vessel, and the synthesis column body module comprises a synthesis column.

The invention discloses a tyrosinase inhibitory peptide from kelp as well as a preparation method and application of the tyrosinase inhibitory peptide. The preparation method comprises the following steps: pretreating kelp, fermenting the kelp by using lactobacillus plantarum, carrying out centrifugation, ultrafiltration and component identification on the obtained fermentation liquor to obtain the composition of kelp polypeptide, screening the tyrosinase inhibitory peptide through molecular docking, and finally carrying out solid-phase synthesis to obtain the tyrosinase inhibitory peptide prepared by the invention. The lactobacillus plantarum fermentation technology is simple and feasible, the production cost is low, equipment is easy to obtain, active ingredients in kelp can be released to the maximum extent, and the prepared polypeptide has the effect of inhibiting the activity of tyrosinase and can be used for developing a tyrosinase inhibitor.

The invention provides an enzymolysis preparation method of a milk-derived taste enhancing peptide, which comprises the following steps: carrying out enzymolysis on a liquid dairy product by using flavourzyme and glutaminase, and then carrying out enzyme deactivation to obtain an enzyme-deactivated product; carrying out acidification centrifugation and ultrafiltration on the enzyme-deactivated product, and freeze-drying the separated effluent to obtain freeze-dried powder; and loading the freeze-dried powder, and separating by a glucose gel column. The product disclosed by the invention does not generate bitter taste, and compared with a sample which is not subjected to enzymolysis, the flavor level of an original skimmed milk product is enriched, and the sample subjected to enzymolysis has the mellow taste of caramel and frankincense. The method comprises the following steps: separating milk-derived taste active peptides from milk-derived taste active peptides, predicting delicate flavor, anti-oxidation and anti-inflammatory activity and ACE blood pressure lowering functional activity of separated peptide liquid through a model, performing taste verification on the peptides predicted to have taste activity through Fmoc solid-phase synthesis, and performing sensory verification on the milk-derived taste active peptides LSFD, EDIKQME, IKQMEAE and TEDELQDK after synthesis, so that the milk-derived taste active peptides are obtained for the first time and are subjected to sensory verification.

The invention discloses a hexapeptide TE6 with xanthine oxidase inhibitory activity and a preparation method and application thereof, and belongs to the technical field of small molecule peptides. The amino acid sequence of the hexapeptide TE6 is TIATVE, and the hexapeptide TE6 can be prepared through a solid-phase synthesis method and an enzymolysis method. The hexapeptide TE6 is identified from a solieria cavaleriei proteolysis solution and has potential interaction with xanthine oxidase, under the concentration of 0.1 mg / mL, the xanthine oxidase inhibition rate is 44.74%, and compared with goose carnosine (the xanthine oxidase inhibition rate is 36.03%), the xanthine oxidase inhibition rate is remarkably increased (plt; 0.05), which is stronger in xanthine oxidase inhibitory activity, and can be used for preparing a preparation for inhibiting xanthine oxidase activity and relieving hyperuricemia.

The invention belongs to the technical field of biology, and particularly relates to polypeptide for promoting proliferation of mesenchymal stem cells and application of the polypeptide. The amino acid sequence of the polypeptide for promoting proliferation of the mesenchymal stem cells is shown as SEQ ID NO: 1. The active polypeptide for promoting proliferation of the umbilical cord mesenchymal stem cells is obtained by adopting a solid-phase synthesis method. Umbilical cord mesenchymal stem cells obtained by culturing the polypeptide have good adherence and multiplication capacities. In addition, the polypeptide can promote Nrf2 gene expression, so that proliferation of the umbilical cord mesenchymal stem cells is effectively promoted.

The invention relates to a molecular tag DMDPM compound, a preparation method thereof and application of the molecular tag DMDPM compound in assisting homogeneous synthesis of heptapeptide H6K, and belongs to the technical field of organic synthesis. The molecular tag DMDPM compound is 2, 4-dimethoxy-4 '-diphenylphosphinyl oxydiphenyl alcohol, and the molecular tag DMDPM compound is 2, 4-dimethoxy-4'-diphenylphosphinyl The method has the advantages of a liquid-phase synthesis method and a solid-phase synthesis method, H6K can be simply, quickly, economically and efficiently synthesized and prepared, and a 2, 4-dimethoxy-4 '-diphenylphosphinyloxy diphenyl alcohol small-molecule auxiliary group (also called as a carrier) can be recycled and directly reused, so that raw material waste is reduced, waste pollution is reduced, the cost is saved, and environmental protection is facilitated.

The present invention discloses a class of bicyclic peptide compounds and their applications, belonging to the technical field of bicyclic peptide compounds. Specifically, the invention relates to the preparation of a fully protected peptide resin using solid-phase synthesis; cleavage and monocyclic cyclization of the fully protected peptide resin to obtain a monocyclic polypeptide; and dicyclic cyclization of the monocyclic polypeptide to obtain a bicyclic peptide compound, wherein the dicyclic cyclization is carried out under the action of iodine methanol and ascorbic acid. The bicyclic peptide compound prepared by the present invention has the following beneficial effects: good safety, low cytotoxicity, good stability, slow degradation rate, good effect on enhancing collagen expression, good effect on enhancing elastin expression, and good effect on inhibiting neurotransmitter release.

The invention discloses a synthesis method of an insulin analogue, which comprises the following steps of: firstly, obtaining A-chain peptide resin by using a solid-phase synthesis method, constructing a disulfide bond between A6 and A11 on a solid phase, and cracking the A-chain peptide resin by using a cracking solution containing a sulfydryl activator to obtain a peptide chain with an activated sulfydryl group and a protected sulfydryl group; then a solid-phase synthesis method is used for obtaining B-chain peptide resin, Lys side chain protecting groups are removed on a solid phase in a fixed-point mode, side chain fatty acid modification is completed, and a peptide chain with an exposed sulfydryl group and a protected sulfydryl group is obtained after cracking is conducted through a cracking solution; and mixing the products in a solution according to a certain proportion to form a first pair of intermolecular disulfide bonds, and constructing and purifying the last pair of disulfide bonds to obtain the insulin analogue. The method disclosed by the invention has the advantages of convenience in synthesis, low cost, simple process and the like, can be used for research on amino acid mutation of insulin compounds, and has important practical significance on development of insulin drugs.

The invention relates to the technical field of dielectric ceramic powder preparation processes, in particular to a multilayer ceramic capacitor, high-activity nano barium titanate powder for the multilayer ceramic capacitor and a preparation method of the high-activity nano barium titanate powder, and the method comprises the following steps: (1) reacting soluble barium salt with a precipitator to obtain barium carbonate precursor particles with high specific surface area; (2) uniformly coating the surfaces of the barium carbonate precursor particles with nano titanium dioxide particles by using a supercritical fluid flash evaporation technology to form a composite precursor; and (3) carrying out solid-phase synthesis reaction on the composite precursor, and sintering to obtain the nano barium titanate powder. Through the synergistic effect of two means of high-activity precursor preparation and nanoscale uniform coating, the composite precursor with extremely high specific surface area, surface energy and microcosmic uniformity is prepared, the thermal sintering temperature is effectively reduced, abnormal growth of crystal grains and lattice distortion are restrained, and the preparation method has the advantages that the preparation process is simple, and the preparation cost is low. The tetragonality of the nano barium titanate powder is obviously improved.

The present application relates to the technical field of dielectric ceramic powder preparation, and particularly relates to a multilayer ceramic capacitor, a high-activity nano-barium titanate powder for the multilayer ceramic capacitor and a preparation method of the high-activity nano-barium titanate powder, the method comprising the following steps: (1) reacting a soluble barium salt with a precipitator to obtain barium carbonate precursor particles with high specific surface area; (2) uniformly coating nano-titanium dioxide particles on the surface of the barium carbonate precursor particles by using a supercritical fluid flash technology to form a composite precursor; and (3) performing a solid-phase synthesis reaction on the composite precursor and sintering to obtain nano-barium titanate powder. The present application, through the synergistic effect of the two means of "high-activity precursor preparation" and "nano-level uniform coating", prepares a composite precursor with extremely high specific surface area, surface energy and micro-uniformity, effectively reduces the heat sintering temperature, suppresses abnormal grain growth and lattice distortion, and significantly improves the tetragonality of the nano-barium titanate powder.

The invention provides a synthesis method of tilpotide, which comprises the following steps: dividing a target peptide chain into six fragments, and adopting bis (4-C18-C28 alkoxy phenyl) methylamine, 2, 4-bis (18-C28 alkoxy)-benzyl alcohol and NH2-Asp (OTAG)-OR1 as hydrophobic label carriers to assist synthesis. A side chain carboxyl group of aspartic acid is innovatively used as an anchoring position of a hydrophobic label, a new fragment connection route is designed, a full-protection tilpotide conjugate is synthesized through a multi-label synergistic effect, and finally a protecting group and a label are removed by using a TFA lysate. Compared with a solid-phase synthesis method, the method is carried out in a homogeneous reaction, the dosage of amino acid and the condensing agent is reduced to 1-1.2 times from 2-3 times, and the cost is remarkably reduced. Compared with an existing hydrophobic labeling method, the method has the advantages that multiple labels can be introduced to serve as protecting groups, the yield and purity of synthesis of medium-chain and long-chain polypeptides are improved, meanwhile, the problem of hydrophobicity attenuation caused by peptide chain extension is solved, and the green chemical process requirement is met.

The invention discloses an agaric polypeptide VR5 with alpha-glucosidase inhibitory activity and a preparation method and application thereof, and belongs to the technical field of small molecule peptides. The amino acid sequence of the auricularia auricula polypeptide VR5 is VGMLR, and the auricularia auricula polypeptide VR5 can be prepared by a solid-phase synthesis method and an enzymolysis method (flavourzyme). The agaric polypeptide VR5 has the beneficial effects that experiments prove that the agaric polypeptide VR5 has very high alpha-glucosidase inhibitory activity, IC50 is equal to 34.96 mu g / mL, the agaric polypeptide VR5 can be used as an alpha-glucosidase inhibitor for preventing or treating alpha-glucosidase mediated diseases, and the agaric polypeptide VR5 can be used for preventing or treating alpha-glucosidase mediated diseases. Or as a hypoglycemic active component, the composition is added into auxiliary hypoglycemic functional food for auxiliary regulation of the blood sugar level of hyperglycemia people.

The invention discloses a polypeptide with DPP-IV (dipeptidyl peptidase-IV) inhibitory activity and application of the polypeptide. Pure peptides APFP and MPFP are obtained through a solid-phase synthesis method, the DPP-IV inhibition IC50 values of the pure peptides APFP and MPFP are measured to be 153.08 mu M and 296.50 mu M respectively, and the DPP-IV inhibition activity of the pure peptides APFP and MPFP is higher than that of partial fragments in the sequences of the pure peptides APFP and MPFP. The peptide fragments APFP and MPFP disclosed by the invention have relatively strong DPP-IV inhibitory activity, can be used for preparing hypoglycemic drugs or foods, and have wide application prospects in industrial application.

The invention relates to a method for semi-solid-phase synthesis of a polycyclic compound and an intermediate, a long chain is synthesized through solid phase, then two-step ring closing is performed to form a key intermediate, and simple derivation is performed on the basis of the key intermediate to obtain a PCSK9 antagonist compound. According to the invention, starting materials for solid-phase synthesis are selected, steric hindrance is effectively avoided, and solid-phase reaction and subsequent liquid-phase correlation cyclization can be smoothly carried out, so that the yield is improved, and the cost is reduced.

The invention relates to the technical field of biochemistry, in particular to an enzyme mutant and application thereof in preparation of conopeptide. According to the preparation method, a strategy of combining green chemistry and an enzyme method is adopted, seven tripeptide fragments are taken as raw materials, a conopeptide main chain is prepared through a liquid-phase synthesis method, and then enzymatic precise modification and synthesis are realized by utilizing a multiple directed evolution enzyme concerted catalysis system. Based on the efficient connection characteristic of a liquid-phase synthesis system and the high substrate specificity of an enzymatic system, the complex protection group operation in traditional solid-phase synthesis is effectively avoided, generation of by-products is remarkably reduced, meanwhile, fixed-point modification and precise assembly of a conopeptide main chain are achieved, and the application prospect is wide. And an efficient and green new path is provided for the continuous production of the cosmetic-grade high-purity conopeptide.

The invention belongs to the technical field of biological small molecule active peptides, and more specifically relates to a uric acid reducing active peptide, a preparation method and an application thereof. The uric acid reducing activity LQKW has remarkable XOD inhibitory activity, IC50 is 2.70 mg / mL, and the IC50 is superior to that of many known natural source XOD inhibitory peptides; good gastrointestinal digestion stability is shown, and the activity retention rate after in-vitro simulated gastrointestinal digestion is (61.84 + / -0.82)%. According to the invention, a specific binding mechanism of uric acid reduction activity and XOD active sites (Ile648, Phe649 and the like) is clarified through molecular docking, and a basis is provided for rational design based on a structure. According to the invention, the method for efficiently preparing the active peptide fragment from the white spirit vinasse is established, and the high-valued utilization of the wine brewing byproducts is realized. The uric acid reducing activity LQKW provided by the invention can be prepared through solid-phase synthesis, the process is mature, the quality is controllable, and a foundation is laid for industrialization. In addition, as the XOD inhibitor of a natural source, the uric acid reducing activity LQKW has good safety.

The invention discloses an oligonucleotide synthesis process of a sulfo-PMO structure. In the oligonucleotide synthesis process of the sulfo-PMO structure, the molecular structural formula of sulfo-PMO is shown in the specification. According to the invention, the molecular structure of thio-PMO is specifically limited, and the synthesis of nucleotide phosphate amide and (thio) phosphoric acid amide in the solid-phase synthesis oligonucleotide is carried out along the direction from 5'to 3 ', that is, in each cycle period, the O5'or O6' position of the nucleotide phosphate amide and (thio) phosphoric acid amide monomer is firstly subjected to coupling reaction, and then the protecting group is removed at the O3 'or N3' position, so that the oligonucleotide phosphate amide and (thio) phosphoric acid amide are obtained. And releasing active hydroxyl or amino / amido to enter the next cycle. The protecting group adopted by the sulfo-PMO molecule is consistent with the protecting groups of other nucleotides, so that the conversion rate of each step of coupling reaction can be conveniently detected on line.

The invention relates to the technical field of polypeptide drug preparation methods, and provides a preparation method of retaglutide and a preparation method of a retaglutide intermediate.The preparation method of the retaglutide comprises the steps that a fragment 1-resin is prepared through a solid-phase synthesis method, then a fragment 2 and the fragment 1-resin are coupled through the solid-phase synthesis method, and the retaglutide is obtained. And cracking the retaglutide-resin, so as to obtain the retaglutide. Wherein the fragment 1 is a 15th-39th amino acid polypeptide fragment, and the fragment 2 is a 1st-14th amino acid polypeptide fragment. According to the preparation method disclosed by the invention, the production cost of the retaglutide can be greatly reduced, the synthesis steps are few, the subsequent treatment is simple, and the purity and the yield of the retaglutide are improved.

The invention discloses a long-afterglow self-luminous material based on multi-element rare earth synergistic sensitization and a preparation method thereof. SrAlO is used as a matrix, trap level distribution is optimized through ternary rare earth synergistic doping according to the molar ratio of Eu to Dy to Nd being 1: (0.4-0.6): (0.2-0.4), and a ZnO nanorod array is grown on the surface of a light-emitting core in an in-situ epitaxial mode to improve the light extraction efficiency; and a hydrophobic modified SiO core-shell coating layer with an ordered mesoporous channel is combined, and oxygen diffusion is promoted by utilizing a nanopore channel so as to accelerate trap regeneration and synchronously inhibit non-radiative recombination. The afterglow time of the material is not less than 8 hours, and the afterglow retention rate after aging at 60 DEG C is not less than 80%. A solid-phase synthesis process and red mud / fly ash industrial solid waste raw materials are adopted, and the carbon emission intensity is smaller than or equal to 6 kgCO / kg. The material can be widely applied to the fields of green traffic infrastructures such as expressways and tunnels.

The present invention discloses a method for improving the stability of solid-phase synthesized multi-cysteine ​​polypeptides, primarily addressing the technical problem of poor stability caused by the susceptibility of such polypeptides to oxidation, degradation, elimination, denaturation, and inactivation. The method comprises the following steps: 1) purifying the multi-cysteine ​​polypeptide synthesized by solid-phase synthesis via liquid chromatography to obtain a preparation solution containing trifluoroacetate; 2) passing the preparation solution through a depth filter containing hydrophilic silica aerogel spheres as a filter material to remove metal ions and trace peroxides contained in the preparation solution by adsorption; 3) further passing the preparation solution through a weakly basic cation exchange resin to a pH of 6.3-6.5; 4) removing the sodium trifluoroacetate in the preparation solution by tangential flow filtration with low pressure, obtaining a weakly acidic, salt-free preparation solution; 5) freezing and vacuum drying to obtain a solid powder final product; 6) vacuum packaging and frozen storage; and 7) ensuring purity and stability after storage in accordance with scientific research requirements.

The application relates to a synthesis method of an anti-freezing glycopeptide polypeptide and belongs to the technical field of polypeptide drug synthesis. The method comprises the following steps: 2-CL-Resin is used as a carrier resin, under the condition of adding an activating agent, the carrier resin and alanine are coupled to obtain Fmoc-Ala-2-CL-Resin; according to the amino acid sequence of the anti-freezing glycopeptide, other amino acids are sequentially coupled through a solid-phase synthesis method; after a protecting group is removed and the carrier resin is cleaved, the anti-freezing glycopeptide crude peptide is obtained; and after purification, salt conversion and freeze-drying, the anti-freezing glycopeptide polypeptide is obtained. The method has the advantages of short synthesis period, low cost, easy post-treatment, few by-products, high product yield, facilitation of large-scale production of the anti-freezing glycopeptide, and considerable economic applicative value and wide application prospect.

The invention discloses a method for high-temperature solid-phase synthesis of a spessartite ceramic membrane with a catalytic function and application of the spessartite ceramic membrane, and belongs to the technical field of functional ceramic composite materials and preparation of the functional ceramic composite materials. The problems that an existing ceramic membrane with a catalytic function is low in permeation flux and low in catalytic efficiency are solved. Aluminum oxide, silicon dioxide and manganese dioxide are used as raw materials, a high-temperature solid-phase synthesis method is adopted, and in the sintering process of the ceramic membrane, aluminum oxide, silicon dioxide and manganese dioxide in membrane holes are subjected to a solid-phase synthesis reaction to generate spessartite (Mn3Al2 (SiO4) 3) with high catalytic activity, so that the combination of a catalyst and the ceramic membrane is tighter, and the catalytic activity of the catalyst is improved. The problems that the catalyst is lost and the membrane holes are blocked and the permeation flux is reduced due to the fact that the catalyst enters the membrane holes in the traditional ceramic membrane preparation process are effectively prevented. Meanwhile, through the space confinement effect of the membrane holes, the free radical concentration in the membrane holes is improved, and the pollutant removal efficiency is enhanced.

The invention provides a dipeptide capable of rapidly supplementing methionine and application thereof, and belongs to the field of nutritional and functional food. The problems of quickly supplementing methionine and promoting lactation are solved. The preparation method comprises the step of preparing the dipeptide GM of which the C terminal is methionine through solid-phase synthesis. The dipeptide GM can be used for supplementing methionine, and it is verified that compared with EM, KM and MM, the dipeptide GM has the higher methionine absorption rate in cells based on the PepT1 vector. The dipeptide GM can also be used for promoting lactation, and it is verified that the dipeptide GM has a better lactation promoting effect compared with EM, KM and MM.

The invention relates to the field of biological medicine, and discloses a pTH long-acting polypeptide compound as well as preparation and application thereof. According to the polypeptide, at least one amino acid residue of the 13th, 26th and 27th amino acid residues of a pTH (1-34) parent peptide sequence is connected with octadecanedioic acid or eicosanoic acid and a derivative modification group of octadecanedioic acid or eicosanoic acid, and the polypeptide is covalently combined with a polypeptide skeleton through an AEA-AEA-gamma-Glu connecting unit. The binding capacity of the polypeptide and serum albumin is remarkably enhanced by utilizing a fatty acid side chain modification means, and meanwhile, the half-life period is prolonged. The pTH long-acting polypeptide compound disclosed by the invention has remarkable osteogenic activity promoting effect, can promote proliferation of MC3T3-E1 cells and generate osteogenic markers and calcium nodules under osteogenic induction conditions, and the binding capacity of the pTH long-acting polypeptide compound and serum albumin is improved by 2-6 times. The invention further provides a solid-phase synthesis method of the polypeptide compound and a pharmaceutical composition containing the polypeptide compound, the polypeptide compound can be used for treating osteoporosis and parathyroid hypofunction, and the compliance problem that an existing medicine needs to be injected every day is effectively solved.

The invention discloses a low-temperature solid-phase synthesis cobalt blue pigment preparation method, which comprises: (1) placing a cobalt source, an aluminum source and an inert template dispersant in a planetary ball mill, carrying out ball milling, and drying to obtain nanometer composite precursor powder; (2) adding a mixture of a lithium source and a boron source into the nano composite precursor obtained in the step (1), putting the mixture into a mortar, and mechanically mixing to obtain a mixed material; and (3) putting the mixed material obtained in the step (2) into a muffle furnace, melting and calcining, cooling to room temperature along with the furnace, grinding, washing with hot water, and drying to obtain cobalt blue pigment powder. According to the method, the synthesis temperature is low, particle coarsening and sintering caused by high temperature are avoided, the energy consumption is low, the process is green, and the obtained cobalt blue pigment is pure in chromaticity, large in specific surface area and excellent in thermal stability.

The application provides a mung bean protein salty taste enhancing peptide, a screening and preparation method and application. The method comprises the following steps: step 1, carrying out step-by-step enzymolysis on mung bean protein by using alkaline protease and flavor protease, carrying out ultrafiltration grading, and screening an initial extract of the salty taste enhancing peptide by using an electronic tongue; step 2, further identifying polypeptide sequences by using LC-MS / MS; and step 3, screening polypeptides with strong interaction capability with salty taste receptors TMC4 and ENaC by combining biological activity prediction, target active fragment screening, safety and physicochemical property evaluation and molecular docking analysis. The salty taste enhancing peptide of the mung bean protein obtained by screening comprises polypeptides represented by RPFF, APDLRGY, WDDIGGL, FDGF and AEFF, and contains RP, RG, DD, DGF and FF characteristic peptide segments, respectively. The polypeptides are synthesized by using a solid phase, and the salty taste enhancing effect of the polypeptides is verified by using an electronic tongue. When 0.03% of the above synthesized polypeptides are added to a 0.4% NaCl solution, the salty taste enhancing rates are 90%, 62%, 34%, 52% and 42%, respectively. The polypeptides can significantly enhance salty taste perception of a solution under low-salt conditions, and achieve the effect of salt reduction without taste reduction.

The invention discloses uric acid-reducing peptide goat milk powder and a preparation method thereof, and belongs to the technical field of enzymes. According to the process for preparing the uric acid lowering peptide by hydrolyzing goat milk through the compound enzyme, the total addition amount of the compound enzyme (the enzyme activity ratio of neutral protease N to neutral protease X is 1: 1) is 4000 U / g-6000 U / g, enzymolysis is conducted for 2-3 h at the temperature of 45-55 DEG C, and under the condition, the xanthine oxidase inhibition rate is 71.67 + / -1.32%-83.64 + / -0.98%. The enzymolysis goat milk containing the uric acid-reducing peptide is subjected to spray drying to prepare the uric acid-reducing peptide goat milk powder, and the storage stability of the goat milk powder is relatively good. The amino acid sequence and the source of the uric acid lowering peptide are separated and identified, the in-vitro uric acid lowering activity of the uric acid lowering peptide is verified through the solid-phase synthesized uric acid lowering peptide, and a theoretical basis and technical support are provided for development of new uric acid lowering peptide goat milk products.

The invention relates to the technical field of biological medicines, and particularly discloses synthesis and application of oligonucleotide with a spacer group embedded between 5-terminal oxygen and thiophosphoric acid. The chemical modification strategy comprises the following steps: preparing a modified nucleotide phosphoramidite monomer in which a spacer group is embedded between O5'and thiophosphoric acid P (V); performing solid-phase synthesis on the modified nucleotide phosphoramidite monomer to construct a target oligonucleotide molecule; a spacer group is embedded between oxygen at the 5 '-terminal of the oligonucleotide and thiophosphoric acid P (V) to form a 5'-terminal thiophosphoric acid structure; as the terminal modified thiophosphoric acid belongs to a non-phosphatase substrate, the terminal modified thiophosphoric acid can resist exonuclease degradation and improve the biological activity of siRNA after being modified.