11 results about "Protein secondary structure" patented technology

The invention discloses a water-soluble silk fibroin with a random crimp / Silk I structure as a main structure as well as a preparation method and application of the water-soluble silk fibroin. The silk fibroin product is characterized in that in a protein secondary structure, the total content of random curls and Silk I structures exceeds 85%, and the proportion of Silk I in the whole crystal structure is not lower than 75%; the product can be directly dissolved in water at room temperature to form a stable clarified solution with the concentration not lower than 5%, and is not gelatinized after being stored at 4 DEG C for 90 days. The preparation method comprises the following steps: degumming and cleaning the mulberry silk raw material; the method comprises the following steps: carrying out short-time (less than or equal to 20 minutes) high-temperature dissolution by adopting a multi-element solution dissolution system with a specific ratio, and then carrying out dialysis purification at a low temperature by taking the conductivity (lt, 10 [mu] S / cm) of a dialysis external liquid and the concentration (lt, 50 ppm) of calcium ions as double end-point standards. The directional regulation and control of the silk fibroin structure are realized through the accurate control of the whole process, and the obtained product has excellent water solubility, storage stability and biological safety, and can be widely applied to the fields of drug delivery, 3D biological printing, medical beauty filling, tissue engineering and the like.

The application belongs to the technical field of cottonseed meal processing and animal feed, and particularly relates to application of enzymatic cottonseed meal in preparation of low-protein daily ration, promotion of animal intestinal development, improvement of animal production performance and improvement of carcass quality, wherein the small peptide content, free amino acid content and antioxidant activity of the enzymatic cottonseed meal are all significantly improved compared with cottonseed meal, the change of protein secondary structure and the significant reduction of relative molecular weight are more conducive to promotion of animal absorption of small molecules, are beneficial to animal intestinal health development, and can effectively improve animal growth performance. The feed prepared by replacing part of the conventional feed with the enzymatic cottonseed meal can still achieve the effects of promoting animal intestinal development and improving animal growth performance under the condition that the crude protein content is reduced by 1% to 2% compared with the basic daily ration or the conventional feed, and the feeding cost is significantly reduced compared with the use of the conventional feed.

The invention relates to a preparation method of a flavor carrier based on sea cucumber basic protein, and belongs to the technical field of marine functional food ingredients. The method comprises the following steps: stirring and extracting in an alkaline environment with the pH value of 11.0 + / -0.5, and carrying out isoelectric precipitation and freeze-drying processes to obtain alkaline protein; when the basic protein is combined with a characteristic flavor compound, the content of alpha-helix in a secondary structure of the combined protein is reduced by more than 8%, the content of beta-fold is reduced by about 14%, meanwhile, a random coil structure is correspondingly increased, and the combining capacity of the basic protein to a typical flavor compound is remarkably higher than that of a traditional extracted protein; and a brand new technical approach is provided for high-value utilization of sea cucumber protein and accurate regulation and control of food flavor.

The invention discloses a ferroheme binding site prediction method, system, medium and equipment, and relates to the field of site prediction, and the method comprises the following steps: obtaining protein sequence and structure information; extracting a plurality of physical and chemical attribute features, amino acid embedding features and protein secondary structure features according to the protein sequence and structure information; carrying out fusion operation on the plurality of physicochemical attribute characteristics, determining global evolution characteristics, carrying out time sequence characteristic analysis and fusion on the global evolution characteristics, determining time sequence characteristics, and carrying out nonlinear combination and mapping on the time sequence characteristics to obtain the probability that the unknown protein is the ferroheme binding protein; and splicing the probability that the unknown protein is the ferroheme binding protein, the amino acid embedding feature and the protein secondary structure feature to obtain a spliced feature, and carrying out weighted summation on different parts of the spliced feature to obtain a prediction result of the ferroheme binding site.

This invention discloses a slow-digesting quinoa flour-concentrated milk protein composite gel food and its preparation method, belonging to the field of food processing technology. The invention first protects the composition as a gel food prepared from raw materials containing concentrated milk protein and quinoa flour; the preparation includes premixing quinoa flour and a portion of concentrated milk protein, hydrating them to obtain a premix with a starch-protein network, adding the remaining raw materials, stirring to form a slurry, and then shaping it. The gel food of this invention constructs a dense and continuous starch-protein network. This network, on the one hand, acts as a physical barrier to prevent effective contact between gastrointestinal digestive enzymes and internal proteins, maintaining the stability of the protein's secondary structure, thereby slowing down the rate of protein digestion and hydrolysis in the gastrointestinal tract to achieve slow digestion; on the other hand, it directly improves the product's hardness, chewiness, and other textural parameters, enhances water-holding capacity, reduces water separation rate, optimizes color and flavor, and achieves a synergistic improvement in multiple indicators of edible quality.

This invention belongs to the field of pharmacology and provides the application of demethoxycurcumin and phlorizin in the preparation of drugs that inhibit β-lactoglobulin glycosylation. The synergistic inhibitory effects and mechanisms of demethoxycurcumin and phlorizin on AGEs were systematically investigated. Fluorescence spectroscopy and carbonyl / thiol / amino group assays confirmed that demethoxycurcumin and phlorizin can synergistically inhibit β-lactoglobulin glycosylation at appropriate concentrations. Circular dichroism spectroscopy and other experiments showed that the combined use of the two can better alleviate protein secondary structure changes and aggregation. They competitively bind to the same glycosylation site, synergistically resist oxidation, thereby inhibiting AGEs formation, and synergistically reducing oxidative stress, cell damage, and apoptosis at the cellular level. Therefore, the combined application of these two drugs has potential therapeutic value in intervening in diabetic complications.

The invention discloses an oyster peptide preparation method, which comprises: (1) a raw material activation stage: taking fresh oyster meat, washing with pulse water flow, placing in a DBD plasma reactor, and treating for 12-15 min at a temperature of 40-45 DEG C so as to reduce the protein secondary structure alpha-helix content by 15-20%, the power of the DBD plasma reactor being 300-350 W, introducing nitrogen gas into the DBD plasma reactor, and the flow rate being 2 L / min; (2) a directional enzymolysis stage; (3) a separation stage; (4) targeted deodorization; (5) centrifugal separation; and (6) pulse vacuum drying. According to the method, the enzymolysis efficiency is remarkably improved, efficient enrichment of small molecules is achieved, fishy smell residues are low, and the activity cost is low and is not prone to degradation.

A neurodegenerative disorder biosensing system including at least one plasmonic device including a plurality of plasmonic nanostructures; at least one optical detector; and at least one data processing device including at least one processor configured to process a plurality of absorption spectra determined from the reflected optical infra-red spectra, the plurality of absorption spectra representing time-resolved infra-red absorption by at least one of: (i) first protein secondary structure types formed from neurodegenerative disorder aggregated proteins and (ii) second protein secondary structure types formed from neurodegenerative disorder aggregated proteins. The at least one processor configured to process the plurality of absorption spectrum signals to identify the first protein secondary structure type and the second protein secondary structure type, and to distinguish the identified first protein secondary structure type from the second protein secondary structure type, and to distinguish the identified second protein secondary structure type from the first protein secondary structure type.

The application realizes significant and stable improvement of soybean protein taste by screening 100~1000 Da specific molecular weight chitooligosaccharide and optimizing whole process parameters. The application determines the interaction mechanism of chitooligosaccharide and soybean protein, changes the protein secondary structure through hydrogen bond, electrostatic and hydrophobic interaction, remodels the protein aggregation state and competitively combines with phytic acid, and fundamentally solves the core taste defects of soybean protein such as roughness, astringency and beany taste. The soybean protein product prepared by the application has delicate and warm taste, and at the same time, the nutritional ingredients are maximally retained, which meets the natural and healthy consumption demand. The preparation process does not need special large equipment, has low cost and small energy consumption, is suitable for various raw materials such as soybean protein isolate and soybean protein concentrate, can prepare various form products such as powder and liquid, is widely applied in the fields of food processing, health product research and development, feed additive and the like, and has significant industrial application value and market prospect.

The invention discloses an EGCG-WPH nano-emulsion capable of enhancing the stability of a gel structure, composite gel prepared from the EGCG-WPH nano-emulsion and application of the composite gel. The EGCG-WPH nano-emulsion is a nano-emulsion prepared by mixing an EGCG solution and a WPH solution and adding corn oil, and the EGCG-WPH nano-emulsion can significantly enhance the structural stability of the gel and can enhance the density and elasticity of the gel. The invention also provides a composite gel prepared by mixing the EGCG-WPH nano-emulsion and a myofibrillar protein solution, the composite gel has freeze-thaw tolerance, and the composite gel after repeated freeze-thaw cycles can continue to maintain a protein secondary structure and water retention capacity. Meanwhile, the freezing and thawing cycle can also enhance the strength of ionic bonds and hydrogen bonds in the composite gel. The invention also provides an application of the EGCG-WPH nano-emulsion and the composite gel in preparation of a minced fillet gel product, and the EGCG-WPH nano-emulsion or the composite gel has a wide application prospect due to the functions of gel stability and freeze-thaw tolerance in gel preparation, has a good economic value and is suitable for popularization and application.

The invention discloses a method for online monitoring protein secondary structure change in a surimi hot processing process based on a hyperspectral imaging technology, and the method comprises the following steps: collecting original hyperspectral data of a surimi sample in a heating process, and determining a protein secondary structure of the surimi sample; performing preprocessing and PCA dimension reduction on the original hyperspectral data to obtain first two principal component diagrams with contribution rates greater than 95%; extracting textural features of the first two principal component diagrams, wherein the textural features comprise local binary pattern (LBP), gray level co-occurrence matrix (GLCM) and two-dimensional discrete wavelet transform (2D-DWT) features; based on the texture features and the spectral features of the original hyperspectral data, establishing and training a PLS prediction model of a protein secondary structure; and monitoring the change of a protein secondary structure in the surimi hot processing process by using the trained PLS prediction model.