5 results about "Antifreeze Peptides" patented technology

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 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 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.