14 results about "Antifreeze Peptides" patented technology

The invention discloses an anti-hardening protein bar suitable for cold conditions and a preparation method thereof, and belongs to the technical field of food processing. In order to solve the problems of texture hardening and mouthfeel deterioration caused by aggregation and crosslinking of protein molecules in the existing protein bar under a cold condition, the invention provides a method for organically combining specific plant proteins (soybean protein, quinoa protein, winter rapeseed protein and pea protein) rich in antifreeze peptide with antifreeze polysaccharide; the protein bar which can effectively resist hardening and keep good texture and nutritional characteristics in a cold environment is prepared through the processes of extrusion puffing, precise mixing, forming and the like, so that the application of the product in the fields of exercise and fitness, outdoor exploration, emergency storage and the like is expanded, and the market competitiveness of the protein bar is enhanced.

The application discloses a preparation method of polyelectrolyte nanoemulsion for frozen meat preservation and an ice-coating method of the polyelectrolyte nanoemulsion, and has the characteristics that the method comprises the following steps: 1) filtering the thawing juice of collected frozen meat, and then performing ultrafiltration centrifugation by using a 8-10 kDa filter membrane; taking the filtrate, and obtaining an antifreeze peptide powder through freeze-drying; 2) slowly adding water-soluble sodium carboxymethyl cellulose into a chitosan solution to make the final mass concentration of the sodium carboxymethyl cellulose be 0.6-1%, and simultaneously adding the antifreeze peptide powder to make the final mass concentration of the antifreeze peptide powder be 6-10%, and then magnetically stirring to obtain a matrix aqueous solution; and 3) adding soybean oil containing essential oil drop by drop into the matrix aqueous solution with a volume of 8-12 times of the soybean oil, homogenizing by using a high-speed homogenizer, and then performing homogenization treatment by using a high-pressure homogenizer, and repeating the homogenization and the homogenization treatment for 3-8 times, so as to obtain the polyelectrolyte nanoemulsion, and the polyelectrolyte nanoemulsion has the advantages of good adhesion, good preservation effect, the ability to improve the quality of the frozen meat and the ability to prolong the shelf life of products.

The invention relates to the technical field of biotechnology, enzyme engineering and biological pharmacy, in particular to a ribonuclease purification production method. According to the method, a deep sea antifreeze polypeptide and rare earth nanocrystal composite bionic system is constructed, quorum sensing signal molecules and a pulsed electric field are introduced in a fermentation stage for two-factor regulation, and a light-operated micro-fluidic chip selective extraction technology is combined, so that efficient separation of target enzyme is realized. A double-ligand magnetic microsphere chromatographic column is innovatively adopted for gradient elution, and the enzyme activity retention rate and the long-term storage stability are remarkably improved through thermotropic liquid crystal capsule stabilization and radio frequency assisted freeze drying processes. According to the invention, the destructiveness of the traditional chromatography technology to enzyme conformation is broken through, the problem of batch fluctuation caused by multi-step purification is solved, a ribonuclease product with high purity, high activity and environmental response characteristic is provided for the field of biological medicine, and the ribonuclease is especially suitable for industrial preparation of gene therapy products and virus vectors.

The present invention relates to the technical field of polypeptides, and particularly relates to an antifreeze peptide from fish scales, a method for screening the same based on bioinformatics, and an application thereof. The amino acid sequence of the antifreeze peptide from fish scales is: IAQPQEKAPDPY; the sites where it forms hydrogen bonds with ice crystals include GLU6, ASP10, and TVR12. The screening method is as follows: the peptide sequence obtained by mass spectrometry analysis of the crude extract of the antifreeze peptide from the scales of Pagellus acarne; the optimal conformation peptide sequence obtained by screening the peptide sequence and the ice crystal prism plane through molecular docking software; under three-dimensional analysis, the antifreeze peptide sequence obtained by screening from the optimal conformation peptide sequence with the number of formed hydrogen bonds as an index. The antifreeze peptide provided by the present invention has high antifreeze activity and can be used as an application in products such as antifreeze agents. The screening method of the present invention simplifies the cumbersome steps such as separation and purification, and the method is simple.

The present invention relates to the technical field of polypeptides, and particularly to an antifreeze peptide from the scales of Dentex tumifrons, a screening method therefor, and an application thereof. The antifreeze peptide from the scales of Dentex tumifrons has an amino acid sequence of: NAITDVVPAPK; the screening method is as follows: the peptide sequence obtained by mass spectrometry analysis of the crude extract of the antifreeze peptide from the scales of Dentex tumifrons; the optimal conformation peptide sequence obtained by screening the peptide sequence and the ice crystal prism plane through a molecular docking software; under three-dimensional analysis, the antifreeze peptide sequence obtained by screening from the optimal conformation peptide sequence with the number of hydrogen bonds formed as an index. The antifreeze peptide provided by the present invention fills the blank of the antifreeze peptide from the scales of Dentex tumifrons, and has high antifreeze activity, and can be used as an application in products such as antifreeze agents. The screening method of the present invention simplifies the cumbersome steps such as separation and purification, and the method is simple.

The invention belongs to the field of cryopreservation agents, and particularly relates to a design method of antifreeze polypeptide, a polypeptide-based cryopreservation protective agent and a preparation method and application of the polypeptide-based cryopreservation protective agent. The polypeptide-based cryopreservation protective agent comprises antifreeze polypeptide, small molecules and a buffer solution, and the negative charge density of the antifreeze polypeptide is 5-25%. The cryopreservation protective agent disclosed by the invention has good biocompatibility. Wherein small molecules are used as a natural osmotic pressure regulator, can enter cells to regulate osmotic pressure balance, and can inhibit formation and growth of ice crystals in the cells; the antifreeze polypeptide is simple in structure, so that the problem of immunogenicity of natural antifreeze protein is solved. The synergistic effect of the two can effectively inhibit the growth and recrystallization of ice crystals, form a round and fine ice crystal morphology, protect cells from mechanical damage during cryopreservation, and improve the survival rate and function of frozen cells. As a preferable form of the invention, the erythrocytes are preserved in liquid nitrogen by using the cryopreservation protective agent, the survival rate of the recovered erythrocytes reaches 93%, and the morphology and oxygen carrying functions of the erythrocytes are retained.

The invention belongs to the technical field of biological polypeptides, and particularly discloses a tilapia skin antifreeze peptide as well as a preparation method and application thereof. The antifreeze peptide is any one of PQGPVGNTGPKG, LSGPTGEAGRE and GGRGPEGPAGAR, the molecular weight of the antifreeze peptide is small, and the structure of the antifreeze peptide is clear. A plurality of amino acid residues in the antifreeze peptide, including Pro, Glu, Gly, Thr, Ser, Leu and Arg, synergistically participate in combination with ice crystals. Through comprehensive control of hydrophilicity, charge distribution and hydrophobic interaction, the antifreeze peptide can be stably adsorbed on the surface of an ice crystal, so that an excellent antifreeze structure foundation is provided. The antifreeze peptide provided by the invention can effectively inhibit the formation and growth of ice crystals under a low-temperature or freeze-thaw condition, and reduce the damage of the ice crystals to a system structure. The compound also has antioxidant activity, and can scavenge free radicals and reduce oxidative stress level, so that common ice crystal damage and oxidative damage in a low-temperature environment are prevented at the same time.

The invention discloses a form-adjustable antifreeze polypeptide nanostructure and a preparation method thereof. The preparation method comprises the following steps: S1, preparing a solution containing polypeptide molecules; s2, quickly freezing the solution in the step S1 into ice, so that polypeptide molecules are enriched at an interface between ice crystals; and S3, regulating and controlling the temperature of the ice obtained in the step S2 to cure the ice crystals, so that the polypeptide molecules are self-assembled in the confinement space at the interface to form the nano-structure with remarkable anti-freezing activity. An ice-water interface concentration effect is combined with a solvent annealing technology, so that the problem that the self-assembly form of the traditional polypeptide is uncontrollable is successfully solved, and accurate adjustment of the morphology (such as a spherical shape and a rod shape) on the nanoscale is realized. The prepared antifreeze agent can effectively inhibit ice crystal growth and recrystallization at extremely low concentration, and a brand new technical path is provided for developing a new generation of green and low-cost low-temperature protection materials.

The present invention relates to a composition for cryopreservation, comprising: a nucleic acid structure which comprises a scaffold nucleic acid folded at predetermined positions to form multiple strands, and a plurality of staple nucleic acids wherein at least a portion of a sequence thereof comprises a complementary sequence to that of the scaffold nucleic acid, which are bound to at least one of the strands of the scaffold nucleic acid to form a double strand; linkers coupled to at least one of single strands in the nucleic acid structure; and an anti-freezing peptide coupled to at least one of the linkers, so as to exhibit excellent freeze-protection effects, which in turn increase cell viability during cryopreservation of cells and tissues, while retaining original texture of food even when used for freezing the food.

The invention relates to wood frog antifreeze peptide and an extraction method and application thereof, and belongs to the field of biotechnology application. The method comprises the following steps: crushing wood frogs or wood frog tissues, pulping, adding protease for enzymolysis, deactivating enzyme, centrifuging, collecting supernate, passing through an ultrafiltration membrane with the molecular weight cutoff of 3-5kDa, collecting filtrate, and drying to obtain a wood frog antifreeze peptide crude product, thereby further obtaining the purified wood frog antifreeze peptide. The compound has the advantages that the freezing point of a solution can be nondependently reduced, a remarkable heat stagnation effect is shown, formation and growth of ice crystals can be actively inhibited, and the compound is used for preparing food or health-care food for improving the anti-freezing capability and anti-fatigue capability of an organism in a cold environment. The compound is used for preparing a protective agent for protecting biological tissues from physical and chemical damages in freezing, freeze thawing and cold-chain transportation processes, and is used for preparing a plant anti-frost agent, and tissue experiments show that the compound has an excellent protection effect on biological tissue structures, is superior to a traditional anti-freezing agent, and has huge potential in the fields of food preservation and biological sample low-temperature storage.

The present application relates to the technical field of peptide generation, and provides an artificial intelligence reverse design method and system for multifunctional antifreeze peptide, comprising the following steps: obtaining the three-dimensional structure of a sequence of a natural multifunctional antifreeze peptide collected in a public database through a protein / peptide three-dimensional structure prediction model; calculating the two-dimensional infrared spectrum of the sequence; constructing a training set for mapping text information to the two-dimensional infrared spectrum and a training set for mapping the two-dimensional infrared spectrum to the main chain skeleton of the multifunctional antifreeze peptide, completing model training, and obtaining a two-dimensional infrared spectrum generation model and a peptide main chain skeleton generation model; in the reasoning stage, inputting functional text information, obtaining a predicted peptide main chain skeleton and performing refinement, calling a skeleton conditional sequence design module to generate a corresponding peptide sequence; and screening out a peptide sequence meeting a comprehensive evaluation condition as a candidate peptide sequence. Through the method, the efficiency and success rate of reverse design of multifunctional peptides starting from functional requirements are improved.

The invention discloses an antifreeze peptide based on bovine-derived by-products. The amino acid sequence of the antifreeze peptide is such as Seq1, Seq2 or Seq3; the invention also discloses application and a screening method of the antifreeze peptide. The preparation method comprises the following steps: S1, training a machine learning model; S2, constructing a prediction set of virtual enzymolysis; and S3, screening the antifreeze peptide. A comprehensive strategy of screening and reverification in combination with machine learning and virtual enzymolysis technology is researched and adopted, computer screening and in-vitro experiment verification prove that three antifreeze peptides CH-11 and CH-15 are obtained from cattle hide collagen and OB-18 are obtained from cattle blood, and through combination of machine learning and virtual enzymolysis, the antifreeze peptide is obtained. The novel antifreeze peptide can be efficiently excavated, key hydrolysis parameters of the novel antifreeze peptide can be determined, a new direction is provided for high-value conversion of bovine-derived by-products, and a high-quality natural antifreeze candidate is provided for the field of meat product freezing protection.

The application discloses a source of antifreeze peptide of euphausia superba for quality keeping of squid and a preparation and screening method thereof, and is prepared from the euphausia superba as raw material, and different proteases are used for enzymolysis under certain material-liquid ratio conditions, and the enzymolysis liquid with the optimal antifreezing effect is screened through a freeze-thaw cycle food model. The euphausia superba enzymolysis liquid obtained through neutral protease enzymolysis can significantly improve the water holding capacity of food, and reduce thawing loss rate and cooking loss rate. After the euphausia superba enzymolysis liquid is prepared under the optimal hydrolysis condition, the molecular weight distribution is determined, then the enzymolysis product is separated and purified through ultrafiltration and dextran gel chromatography, the active component is identified through liquid chromatography-tandem mass spectrometry, finally, the potential active peptide is screened and mechanism analysis is carried out, and the antifreeze peptide is successfully identified. The prepared antifreeze peptide is natural, safe and effective in source, is suitable for quality keeping of frozen aquatic products and other frozen foods, and has a good application prospect.

The invention discloses an ice crystal recrystallization inhibitory peptide, the structure of which is as follows: X1-X2-Val-Thr-X3-X4-Met-X5, in the formula, X1 is Leu or Ile; x2 is Ile, Ser, Val or Thr; x3 is Gln or Asn; x4 is Thr, Val or Ser; and X5 is Lys or Arg. The invention also provides an application of the ice crystal recrystallization inhibiting peptide as an antifreeze peptide. The ice crystal recrystallization inhibitory peptide provided by the invention can be used as a food antifreeze additive or cryoprotectant, and the addition amount is only 2.0-5.0 mg / mL. The ice crystal recrystallization inhibitory peptide provided by the invention has strong ice crystal recrystallization inhibitory activity, the addition amount is about 10% of that of similar peptides reported in current literatures, and the product preparation method is simple, natural, safe and suitable for industrial application.