7 results about "Peptide fragment" patented technology

The invention belongs to the technical field of biology, and particularly relates to a characteristic polypeptide for identifying the deer-horn glue of Cervus nippon or Cervus elaphus, and application of the characteristic polypeptide. The characteristic polypeptide provided by the invention is as follows: a peptide fragment 1 is as shown in SEQ ID No. 1: ASTGAALVVR; and a peptide fragment 2 is as shown in SEQ ID No. 2: TPVGQGPSVPVPNR. The characteristic polypeptide and the detection method provided by the invention provide reference for searching a characteristic peptide fragment in related species lacking in a database. The characteristic polypeptide provided by the invention has excellent specificity and stability for the deer-horn glue of the Cervus nippon or the Cervus elaphus, is high in specificity, can be used for identifying deer-horn glue medicinal materials and Chinese patent medicines added with the the deer-horn glue medicinal materials, and has a good application prospect.

The invention belongs to the field of protein analysis, and relates to a new method for enrichment of a glycosylated peptide through a magnetic nanometer material modified by aminoxy, in particular to a method for solid-phase enrichment and mass spectrographic analysis of a glycosylated peptide fragment. The method comprises the following steps: firstly, using sodium periodate NaIO4 to oxidize a hydroxyl group on a glycopeptide to change the hydroxyl group to an aldehyde group; secondly, placing the magnetic nanometer material Fe3O4@ONH2 modified by aminoxy to an oxidized glycopeptide solution, and fixing the glycopeptide to the magnetic nanometer material through reaction of an aminoxy group and the aldehyde group obtained after a sugar chain in the glycopeptides is oxidized; thirdly, cleaning to remove non-glycopeptide which does not react with the nanometer material; finally, dissociating the captured glycopeptide from the material by use of sugar chain enzyme, and realizing mass spectrographic analysis of the glycosylated peptide. The method is simple in step, convenient to operate, high in speed and efficient, and can realize highly-sensitive and highly-selective mass spectrometric analysis of the glycosylated peptide.

The invention relates to an immobilized enzyme based protein enzymolysis method. The method adopts temperature sensitive microspheres as the immobilized enzyme carrier, performs temperature regulationof the hydrophilic and hydrophobic properties of the temperature sensitive immobilized enzyme microspheres so as to control the protein enzymolysis process, i.e. when the enzymolysis temperature is higher than a critical phase inversion temperature of the temperature sensitive immobilized enzyme microspheres, the microspheres are hydrophobic, while a to-be-tested protein sample is enriched, enzymolysis is carried out on the microspheres, when the enzymolysis temperature is lower than the critical phase inversion temperature of the temperature sensitive immobilized enzyme microspheres, enzymolysis is stopped and peptide fragment is released, thereby improving the enzymolysis efficiency and detection rate of the sample peptide fragment. The protein enzymolysis method provided by the invention has the characteristics of simple steps, convenient operation and the like, and is conducive to research of proteomics and related fields.

The invention discloses an efficient preparation method of low-value fish immunomdodulating peptides, relates to the development and utilization of low-value fish bioactive peptides and related anti-inflammatory drug products, and belongs to the technical field of low-value fish processing; the preparation method comprises the steps of preparing nemipterus virgatus myosin by a salt extraction method, fully expanding a high-spiral structural domain of myofibrillar protein by using a high-pressure homogenization method; fine-tuning a protein solution to pH 7.5, adding trypsin, performing enzymatic hydrolysis for 90 minutes, promoting an ultrafiltration membrane to separate a nemipterus virgatus protein enzymatic hydrolysate by using impressed current, and obtain a peptide fragment of 500 to3000 components; finally obtaining a powdery product by a freeze-drying method; the method can improve the degree of hydrolysis of the nemipterus virgatus myosin peptide, and the biological propertiesand yield of the immunomodulating peptides; the anti-inflammatory activity of the immunomodulatory peptides prepared by the method is better; the invention realizes the deep processing and comprehensive utilization of the low-value fish, and has important meaning for improving the added value of the low-value fish.

The invention discloses an anti-tumor fusion protein and a preparation method thereof. The fusion protein is prepared in the steps of cloning of VCAM-1 mutants and VEGF165 mutant genes, construction of fusion protein gene plasmids, expression and purification of the fusion protein and the like. The fusion protein has a remarkable inhibitory effect on angiogenesis and has high an antineoplastic effect on gastric cancer. The fusion protein contains two targeted protein fragments of the VCAM-1 mutants and VEGF165 mutants which are connected through flexible peptide fragments, the biological activity is high, the preparation method is simple, the practicability is high, and the protein can be used for preparing various antineoplastic drugs and has broad application prospects.

The invention discloses an immune peptide identification method Alpha-DDA, a terminal device, a readable storage medium and application of a peptide fragment marking method in the field of immune peptide identification, and relates to the technical field of bioinformatics. According to the immune peptide identification method provided by the invention, a retention time deviation score and an ion qualitative feature score are added on the basis of traditional identification features; the immune peptide obtained by identifying the characteristics is more accurate. The recall rate and the accuracy of the method are relatively high, and the method also has a very good F1 value, so that the method is an excellent immune peptide identification scheme for balancing the recall rate and the accuracy. In addition, the application of the peptide fragment N-terminal labeling method significantly enhances the signal intensity of b ions, improves the quality of a secondary spectrogram, and further promotes the accurate recognition of the immune peptide.