246 results about "Peptide fragment" patented technology

The invention relates to the technical field of biology, in particular to multifunctional belly-expanding hippocampal peptide as well as a preparation method and application thereof. Comprising a polypeptide with an amino acid sequence as shown in SEQ ID NO.1. The hippocampus antioxidative peptide is prepared by adopting an ultrahigh pressure pretreatment and enzymolysis technology, the adopted extraction process is simple in route, and the time and the production cost are effectively saved; an animal model is utilized to prove the anti-oxidation effect and the effect of improving male reproductive disorder and testis injury of the multifunctional belly-expanding hippocampal peptide; and on the basis, a novel peptide fragment with high activity, no toxicity and no sensitization is obtained.

The invention discloses an antler bone strengthening peptide for promoting bone repair as well as a screening method and application thereof, and belongs to the technical field of traditional Chinese medicinal material polypeptides. And the antler bone strengthening peptide is one of G40, G44 and G45. Grinding and crushing the antler, homogenizing the lysate, performing ultrasonic centrifugation, precipitating protein with methanol, centrifuging and discarding the supernatant; extracting, desalting, and freeze-drying to obtain a antler polypeptide extract; liquid chromatography-mass spectrometry detection, Peaks 8 search software and De Novo method analysis are adopted, according to the conditions that ALC is larger than or equal to 95%, local context is larger than or equal to 95%, Area is larger than or equal to 1000000 and an NCBI database, free polypeptide is obtained through comparison, the biological activity probability, the peptide fragment toxicity and the sensitization of the peptide fragment are predicted, and candidate polypeptide is obtained; synthesizing candidate polypeptides by a solid-phase synthesis method; the influence of the candidate polypeptide on osteoblast proliferation is evaluated, and the antler bone strengthening peptide is screened out. The antler bone strengthening peptide promotes osteoblast proliferation, and reveals a potential bone repair mechanism of the antler bone strengthening peptide.

The invention discloses an antibacterial peptide fragment intercepted from chitinase IDGF4 protein and application of the antibacterial peptide fragment in preparation of antibacterial drugs. According to the invention, short peptide fragments in chitinase IDGF4 protein are screened, three candidate peptides are obtained through chemical synthesis, the antibacterial performance of the candidate peptides is systematically evaluated, and the evaluation result shows that the peptide fragment with the amino acid sequence as shown in SEQ ID No.2 can effectively inhibit the growth of salmonella and staphylococcus aureus under the concentration of 1mg / mL; the antibacterial effect of the compound is confirmed in inhibition zone experiments, enzyme-labeled turbidimetry and growth curve monitoring, and the compound shows stable and remarkable antibacterial activity and can be used as a novel antibacterial molecule; the invention provides a new candidate sequence for developing the antibacterial peptide with high efficiency and low drug resistance risk, and has application potential in the aspect of preparing clinical antibacterial drugs.

The invention relates to the technical field of biology, in particular to a swelling hippocampal peptide as well as a preparation method and application thereof. Comprising a polypeptide with an amino acid sequence as shown in SEQ ID NO.1. The hippocampus antioxidative peptide is prepared by adopting an ultrahigh pressure pretreatment and enzymolysis technology, the adopted extraction process is simple in route, and the time and the production cost are effectively saved; an animal model is utilized to prove the antioxidation effect and the effect of improving male reproductive disorder and testis injury of the hippocampal swelling peptide; and on the basis, a novel peptide fragment with high activity, no toxicity and no sensitization is obtained.

The invention discloses a fish by-product active peptide, a preparation and application, and belongs to the technical field of biological active peptides. The amino acid sequences of the fish by-product active peptide are shown as SEQ ID NO: 1 to SEQ ID NO: 3. Both the single peptide fragment and the compound peptide fragment of the fish by-product active peptide can obviously inhibit NO secretion of a lipopolysaccharide (LPS)-induced macrophage (RAW264.7) inflammation model, so that the fish by-product active peptide has a relatively good application prospect in preparation of a product with an anti-inflammatory effect; and a foundation is laid for high-added-value utilization of salmon byproducts and promotion of research, development and application of functional active peptides.

The invention relates to the technical field of new material application, and discloses a magnetic bead material for enriching a sulfydryl peptide fragment and a preparation method thereof.The magnetic bead material prepared from micron carboxyl magnetic beads, dodecane dicarboxylic acid dihydrazide and SPSP has a long chemical reaction connecting arm, so that a reaction group has the better freedom degree, the reaction with sulfydryl is better facilitated, and the magnetic bead material can be used for enriching the sulfydryl peptide fragment. The enrichment efficiency is relatively high. When the magnetic bead material is prepared, micron carboxyl magnetic beads and dodecane dicarboxylic acid dihydrazide are based on hydrazine group and carboxyl condensation, the condensation reaction is more selective and more stable, the reaction is carried out under a milder condition, the reaction product is stable, and the reaction efficiency is higher at a lower reaction temperature. Dodecane dicarboxylic acid dihydrazide and SPSP are based on a reaction of N-succinimide and hydrazine, N-succinimide has high specificity to amino-containing molecules, side reactions are reduced, the reaction is generally carried out at room temperature, strong acid and alkali conditions are not needed, and protection of other sensitive groups is facilitated.

The present application provides chimeric proteins comprising an antibody moiety that specifically binds to a component of an influenza virus or a variant thereof, and a positively charged mucoadhesive peptide fragment. Compositions comprising the chimeric proteins described herein are useful for preventing or treating an infection caused by an influenza virus or a variant thereof in an individual.

The invention relates to the technical field of biology, in particular to a swelling hippocampus antioxidative peptide as well as a preparation method and application thereof. Comprising a polypeptide with an amino acid sequence as shown in SEQ ID NO.1. The hippocampus antioxidative peptide is prepared by adopting an ultrahigh pressure pretreatment and enzymolysis technology, the adopted extraction process is simple in route, and the time and the production cost are effectively saved; an animal model is used for proving the antioxidation effect of the hippocampus erectus antioxidative peptide and the effect of improving male reproductive disorder and testis injury; and on the basis, a novel peptide fragment with high activity, no toxicity and no sensitization is obtained.

The invention relates to a recombinant expression cat interferon-omega gene and a preparation method and application thereof, the nucleotide sequence of the cat interferon-omega gene is as shown in SEQ ID NO.1, and the cat interferon-omega gene is obtained by introducing an Fc fusion fragment to the C terminal and / or N terminal of the natural gene sequence of the cat interferon-omega. XTEN or PAS is introduced to prolong a peptide fragment, and original glycosylation modification sites on a natural sequence are reserved. The method comprises the following steps: cloning a cat interferon-omega gene into an expression vector containing double promoters, further transfecting into a cell, carrying out stable cloning and screening, establishing a high-expression cell strain, and carrying out fermentation culture in a bioreactor. According to the invention, the cat interferon-omega gene is subjected to multiple modification and is efficiently expressed in a CHO-K1GS system, so that the protein yield, the stability and the half-life period are remarkably improved; the obtained fusion protein is high in purity and strong in activity, can obviously enhance immune response and protection effect when being matched with cat vaccines, and is good in safety.

The invention discloses synthesized XVII type humanized collagen as well as a preparation method and application thereof, and particularly relates to the technical field of genetic engineering. The amino acid sequence of the recombinant XVII type collagen is as shown in SEQ ID NO. 1. According to the invention, key functional domains (five high-hydrophilicity and high-stability peptide fragments such as 641-685 and the like) in a human XVII type collagen alpha1 chain are retained, and non-functional regions are removed. The 100% human source sequence coverage rate is adopted, the immunogenicity risk of animal source collagen is completely avoided, and the biocompatibility is excellent. The functional peptide fragment is repeated twice to form a stable structure of 210 amino acids, so that the functional activity of the protein is enhanced. The theoretical isoelectric point (pI = 6.07) is close to the pH value (7.4) of human tissue fluid, the dissolvability is excellent, and the applicability is high.

The invention relates to the technical field of polypeptides, in particular to an enzyme-mimetic polypeptide, hydrogel, a preparation method and application, the enzyme-mimetic polypeptide selects a peptide fragment I and a peptide fragment II with biocompatibility and degradability as basic sequences, and the peptide fragment I and the peptide fragment II form a beta folding unit, so that the stability of a polypeptide structure can be enhanced; then, the peptide chain is driven to be self-assembled to form a regular nanofiber structure; according to the invention, the characteristic that the biomimetic polypeptide and metal ions are subjected to a complex reaction to form a chelate is utilized, the transparent and stable hydrogel can be rapidly formed without adding a gelatinizing agent, and TEM, SEM and rheological characterization are carried out on the hydrogel to find that the hydrogel containing the biomimetic polypeptide has a porous nanofiber network structure, so that the biomimetic polypeptide can be used for preparing the hydrogel. Meanwhile, the biomimetic polypeptide hydrogel has the same flexibility as natural tissues, and the characteristics indicate that the biomimetic polypeptide hydrogel is expected to have wide application prospects in the aspects of biomimetic materials, antibiosis, cell culture, drug carriers and the like.

The application belongs to the technical field of biology, and particularly relates to an antibacterial polypeptide LAB-129 and application thereof. The application is based on an antibacterial peptide LAB-4 with antibacterial activity from a Shanxi old vinegar source, adopts a random fragmentation strategy to split the complete sequence into multiple short peptide fragments with 5-50 amino acid residues, and screens a new antibacterial peptide LAB-129 with higher antibacterial activity. Compared with the LAB-4, the LAB-129 has stronger antibacterial activity, lower MIC, higher membrane damage capacity and cell damage effect, and exhibits better overall antibacterial effect, thereby laying a good foundation for developing a new microbial proliferation inhibitor to replace traditional antibiotics.

The invention provides a method and system for discovering antioxidant peptides from food and agricultural by-products and outputting enzymolysis recommendation, and relates to the technical field of bioinformatics and artificial intelligence crossing. The method sequentially comprises the steps of protein sequence collection and standardization, candidate peptide fragment interception, prediction of antioxidant activity through fusion of sequence and structural characterization, generation of releasable peptide fragments through enzyme digestion simulation, and construction of comprehensive evaluation indexes based on activity probability and process parameters. And an optimal enzymolysis scheme is searched in an enzyme combination and reaction condition space through multi-objective optimization, so that the method is suitable for high-valued utilization of food industrial residues and agricultural wastes, and has the advantages of high throughput, high accuracy and high implementability.

The invention relates to a TCR-pMHC combination prediction method, model and system based on deep learning, the TCR-pMHC combination prediction method based on deep learning comprises the following steps: step 1, carrying out data preprocessing operation on an input peptide fragment sequence, an MHC sequence and a TCR sequence; 2, performing pMHC feature extraction operation and TCR feature coding operation; performing pMHC feature extraction operation: performing context feature extraction on the peptide fragment sequence and the MHC sequence subjected to data preprocessing to obtain pMHC features; tCR feature coding operation: coding the TCR sequence subjected to data preprocessing to obtain TCR features; and step 3, TCR-pMHC combined prediction operation: carrying out fusion operation on the pMHC features and the TCR features to obtain an interaction feature vector, and carrying out classification operation according to the interaction feature vector to obtain a TCR-pMHC combined prediction result. According to the invention, through extraction, fusion and classification of the pMHC features and the TCR features, TCR-pMHC combined prediction is realized; and the prediction accuracy can be effectively improved.

The invention discloses a marine-derived bioactive peptide with a blood sugar reducing effect, a preparation and application, and belongs to the technical field of bioactive peptides. The amino acid sequence of the bioactive peptide is at least one of FYP, FPF and YAPFPK. Three bioactive peptides with the blood sugar reducing effect are separated and purified from oysters through enzymolysis, ultrafiltration, gel chromatography, liquid chromatography-mass spectrometry and bioinformatics technologies. According to the present invention, chemical synthesis is performed according to the identified peptide fragment sequence, the hypoglycemic activity of the synthesized single peptide fragment and the compounded peptide fragment is detected, and the bioactive peptides have good alpha-glucosidase inhibition activity, such that the bioactive peptides have good application prospects in the preparation of the products with the hypoglycemic effect, and can be widely used in the preparation of the products with the hypoglycemic effect. And a foundation is laid for high value-added utilization of oysters and promotion of research, development and application of functional active peptides.

The invention relates to the technical field of biology and biology, in particular to a screening method of thermostable mutation sites of a G protein coupled receptor and application of the thermostable mutation sites of the G protein coupled receptor, and the screening method comprises the following steps: S1, replacing a third intracellular ring segment in a wild type G protein coupled receptor with a third intracellular ring sequence of a kappa opioid receptor; marking a SmBiT peptide fragment label on the wild type G protein coupled receptor; s2, mutating a wild type G protein coupled receptor according to a mutation site in the G protein coupled receptor mutant to be detected; s3, incubating the G protein coupled receptor modified in the step S2 at different temperatures to obtain modified G protein coupled receptor samples treated at different temperatures; s4, carrying out mixed incubation on the modified G protein coupled receptor samples treated at different temperatures and a nano antibody-LgBiT compound, then adding luciferase to act as a substrate, and detecting; the method is high in screening efficiency, low in cost and short in time.

The invention discloses a kit and a method for detecting pepsin based on polypeptide, and belongs to the technical field of proteomics. The amino acid sequence of the polypeptide is as shown in SEQ ID No. 1. The polypeptide is obtained based on enzymolysis of pepsinogen PGA4 and screening, the polypeptide and isotope labeled polypeptide are utilized to establish a standard curve, a biological sample is further subjected to enzymolysis to obtain a peptide fragment sample, and pepsin in the biological sample can be quantified by detecting the content of the polypeptide in the peptide fragment sample. By utilizing the method disclosed by the invention, the pepsin in the biological sample can be rapidly quantified, so that pathological reflux and physiological reflux are diagnosed and distinguished, and the accuracy rate is high.

The invention relates to the technical field of giant salamander peptide separation and purification, in particular to a giant salamander peptide extraction and separation and purification method and system.The method comprises the steps that healthy giant salamanders and giant salamander processing equipment are determined, giant salamander processing by-products are obtained, the giant salamander processing by-products are pretreated, to-be-processed by-products are obtained, the to-be-processed by-products are degreased and deodorized, and the giant salamander peptide is obtained. Preparing giant salamander protein dry powder, preparing giant salamander crude peptide liquid, obtaining a target peptide fragment, finely separating the target peptide fragment to obtain target active peptide distillate, freeze-drying the target active peptide distillate to obtain high-purity giant salamander peptide powder, and storing the molecular weight, amino acid sequence and activity verification parameters of the peptide fragment. And extracting, separating and purifying the giant salamander peptide based on the optimized storage database and the giant salamander grease. The extraction efficiency and the separation and purification efficiency of the giant salamander peptide can be improved.

The invention discloses a recombinant humanized type-A type-III collagen, a preparation method thereof and a recombinant bacterium, and relates to the technical field of bioengineering. According to the preparation method, peptide fragments with 100% identical sequences of III-type collagen from human are integrated into host bacteria to obtain recombinant bacteria for efficiently synthesizing recombinant humanized A-type III-type collagen, and the recombinant humanized collagen produced by utilizing the recombinant bacteria does not contain any gene sequence of non-human collagen sources, and has the advantages of high efficiency, high yield, high yield and the like. The collagen has the characteristics of small molecular weight, high yield, high purity, water solubility and the like, and can be widely applied to the fields of skin care products, medical cosmetology, skin repair dressings and the like, so that the recombinant humanized A type III collagen, the preparation method thereof and the recombinant bacteria provided by the invention have better industrial application prospects.

The invention belongs to the technical field of biological drug analysis, and particularly relates to a method and a system for quantitatively detecting antibody drugs by using a dimethyl-labeled modified peptide fragment as an internal standard. Sequentially carrying out dimethyl labeling on the enzymolysis peptide fragments of the antibody drugs to obtain a plurality of dimethyl-labeled modified peptide fragments which are used as internal labels; the method comprises the following steps: enriching antibody drugs in a biological sample, and carrying out enzyme digestion to obtain a plurality of unlabeled modified peptide fragments; and mixing the unlabeled modified peptide fragment with an internal standard, enriching the modified peptide fragment, and then carrying out quantitative detection on the modified peptide fragment by adopting liquid chromatography-tandem mass spectrometry. A one-to-one structural analogue internal standard is provided for the modified peptide fragment, and the matrix effect is eliminated. Meanwhile, the method is combined with a high-pH reversed-phase grading equal peptide fragment enrichment method, so that the detection sensitivity of the modified peptide fragments in the matrix is improved. The technology provides a sensitive and reliable quantitative analysis method for the modified peptide fragment, and can be used for quantitative analysis of antibody drugs in biological samples.

The invention discloses sturgeon cartilage active peptide capable of promoting growth and improving bone development as well as a preparation method and application of the sturgeon cartilage active peptide, and belongs to the technical field of active peptide. According to the invention, sturgeon cartilage is taken as a raw material, polypeptide with the highest activity of promoting bone growth and development is selected from different enzymolysis combinations through MC3T3-E1 cell tests, and the positive effect of the polypeptide is verified through zebra fish tests; then, two potential sturgeon cartilage active peptide sequences with the function of promoting bone growth and development are screened out through bioinformatics technologies such as mass spectrum identification, molecular docking and the like, and the amino acid sequences of the sturgeon cartilage active peptide fragments are shown as SEQ ID NO.2 and SEQ ID NO.5. The sturgeon cartilage peptide prepared by the method disclosed by the invention has the activity of promoting bone growth and development, can solve the problem of high-value utilization of sturgeons, can also be applied to functional products as a functional factor, and has a good application prospect.

The present disclosure provides polypeptides having a cholesterol-lowering function in a soybean protein hydrolysate, a preparation method thereof, and uses thereof. The polypeptides are derived from peptide fragments having a molecular docking “binding energy” value of less than −1.2 kcal with cholesterol esterase. The peptide fragments of the polypeptides that are subjected to molecular docking with cholesterol esterase are derived from 23 polypeptides having a Peptide Ranker bioactivity score of greater than 0.9. The polypeptides possess a significant blood-lipid-lowering function.

The invention discloses a method for detecting exogenous amylase derived from aspergillus in honey and application of the method. The method comprises the following steps: screening and determining a characteristic peptide fragment, pre-treating a sample, making a standard curve, separating by using liquid chromatography, detecting by using tandem mass spectrometry, and quantifying by using an internal standard method. The exogenous amylase characteristic peptide fragment derived from aspergillus is FASYTNDIALAK, and the specific peptide fragment derived from aspergillus is FASYTNDIALAK. The invention establishes a quantitative method for detecting the exogenous amylase derived from aspergillus in the honey by liquid chromatography-tandem mass spectrometry, and the quantitative method has better accuracy and sensitivity and is suitable for adulteration identification of the honey. The method has important practical significance for controlling the quality of honey and maintaining the healthy and sustainable development of the bee product industry.

The invention relates to the field of nutritional health food, and discloses a casein modified active peptide for promoting bone repair and a preparation method thereof.The structure of the active peptide sequentially comprises a bone targeting sequence with high affinity to hydroxyapatite, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions and a casein phosphopeptide core sequence capable of chelating calcium ions from the C-terminal to the N-terminal. The digestion sequence can be specifically hydrolyzed by matrix metalloproteinase, and the alkynyl functional group is used for covalent cross-linking. The active peptide can be mixed with an azido-containing multi-arm cross-linking agent, and hydrogel can be rapidly formed under physiological conditions through cycloaddition reaction. The system can be gelated in situ and anchored to a bone defect part in a targeted manner, and is triggered by a specific enzyme in a pathological microenvironment to controllably release active peptide fragments capable of chelating calcium ions, so that the concentration of local mineral ions is adjusted, the cell living environment is improved, and an effective new way is provided for promoting bone repair.

An objective of the present invention is to provide a novel biomarker for predicting the prognosis of an endometrial cancer patient. A biomarker that comprises a claudin 6 protein or a peptide fragment thereof, or a transcription product of a claudin 6 gene or a nucleic acid fragment thereof is provided so as to predict the prognosis of an endometrial cancer patient.

The invention provides a polypeptide for activating cellular immunity in chronic hepatitis B and application of the polypeptide, and belongs to the technical field of biological medicine. A polypeptide library is designed and synthesized on the basis of a preS1 structural domain for coding HBV large HBsAg, a full-length core protein Core, a polymerase protein fragment rich in T cell epitopes and an mRNA-PreS1CPX holoantigen sequence (as shown in SEQ ID NO.1) of full-length X protein HBX, and peptide fragments capable of activating T cell immunity are screened by utilizing ELISPOT and flow cytometry. Experimental results show that the polypeptide sequences as shown in SEQ ID NO.2-15 can promote HBV antigen specific immune response by stimulating CD8 + T lymphocytes to secrete IFN-gamma, so that immune activation treatment of hepatitis B is realized.

The present disclosure provides a carrier peptide fragment with excellent cell membrane permeability. The carrier peptide fragment disclosed herein includes the following amino acid sequence set forth in SEQ ID No.: 1: KKRTLRKSNRKKR, and a lysine residue at a 12th position from an N-terminus of the amino acid sequence is a D-form, and the other amino acid residues are L-forms.

The invention discloses a sea-buckthorn small molecule peptide and a preparation method thereof, and relates to the field of biological medicine and food processing. According to the method, sea-buckthorn pulp residues and sea-buckthorn seed residues are used as composite raw materials and are mixed and stirred to form homogenate, and then cell wall structures are destroyed through ultrasonic wall breaking treatment to release protein components; then cutting off a peptide bond under the action of compound enzymes (plant protease, neutral protease and pepsase) by adopting an ultrasonic-enzyme synergistic hydrolysis process to generate a small molecule peptide fragment; after removing impurities through centrifugal separation, purifying through an ultrafiltration membrane (the molecular weight cut-off is 1-3kDa) to obtain a small molecule peptide solution; and performing debitterizing treatment by using macroporous adsorption resin, and preparing sea-buckthorn small molecule peptide powder by using a vacuum freeze-drying technology. According to the method, through ultrasonic-enzyme synergistic interaction, multi-stage purification combination and low-temperature keep-alive processes, the yield, molecular weight uniformity and antioxidant activity of small molecular peptides are remarkably improved, and high-valued utilization of sea-buckthorn processing by-products is achieved.

A preparation method for semaglutide. The method comprises: producing a semaglutide resin by means of a solid-phase synthesis, producing crude semaglutide by cleavage and deprotection, producing refined semaglutide by purification and freeze-drying, comprising the solid-phase synthesis of a semaglutide 1-6 peptide fragment resin, which is cleaved and purified to serve as a first peptide fragment; and synthesizing a lysine having a sidechain group at locus 20 of semaglutide to serve as a second peptide fragment. In the method, prepared is a semaglutide loci 1-6 fully protected peptide fragment, which serves as a key starting material applied in the solid-phase synthesis of semaglutide, thus reducing the generation of D-His, D-Glu, D-Thr, D-Phe racemic impurities and +Gly impurities, reducing the difficulty of coarse product purification, increasing the purity and yield of semaglutide, reducing synthesis costs, and favoring industrialized large-scale production.

This invention relates to the fields of molecular biology and biomedicine, disclosing plasma-active peptides with antithrombotic effects and their uses. The invention obtains various active peptides from plasma through screening and solid-phase synthesis, and confirms their biological activity through in vitro platelet aggregation experiments and in vivo arterial thrombosis model experiments. Results show that peptides 1957, 1960, and 1961 significantly inhibit collagen-induced platelet aggregation, exhibiting good antiplatelet activity; animal experiments show that peptides 1955, 1957, 1960, and 1961 significantly inhibit arterial thrombosis. These active peptides are derived from endogenous plasma components, belonging to natural antithrombotic substances, possessing good physiological compatibility and safety advantages, and reducing the risk of immunogenicity and adverse reactions. These peptides can exert antithrombotic effects without relying on traditional antiplatelet drugs, providing a new source of active molecules and treatment options for the prevention and treatment of thrombotic diseases.