35 results about "Protein Cleavage" patented technology

The present invention provides a method for selectively collecting the N-terminal peptide fragments of a protein of interest whether or not the protein of interest is modified on the N-terminus. A method for selectively collecting the N-terminal peptide fragment of a protein, comprising: a protection step (1) of protecting side chain-amino groups of amino acid residues containing side chain-amino groups of a protein of interest to obtain a protected protein protected on the side chain-amino groups; a fragmentation step (2) of cleaving the protected protein into one N-terminal peptide fragment (a) containing the N-terminus of the peptide of interest and one or more of peptide fragments (b) other than the N-terminal peptide fragment (a); and a separation step (3) of separating the N-terminal peptide fragment (a) from the other peptide fragments (b) by selectively eluting the N-terminal peptide fragment (a) based on the difference in their reactivity or affinity to substrate, wherein the selective elution is achieved either by allowing the other peptide fragments (b) to bind to the substrate while allowing the N-terminal peptide fragment (a) to elute, or by allowing the N-terminal peptide fragment (a) to bind to the substrate while allowing the other peptide fragments (b) to elute and subsequently eluting the bound N-terminal peptide fragment (a).

Disclosed are methods for producing peptide standards for quantitative proteomics. In one disclosed embodiment, chimeric polypeptides that are a combination of mass tags for multiple proteins are expressed in a host cell that is grown on an isotopically-altered medium. The mass tags in the chimeric polypeptide are separated by specific cleavage sites (such as trypsin cleavage sites), and upon treatment with an appropriate protein cleavage agent (such as trypsin) the constituent peptide standards are released. Methods of mass spectrometric analysis that employ the disclosed chimeric polypeptides (or the peptide standards liberated therefrom) also are disclosed.

The invention discloses a soybean peptide for promoting lactobacillus proliferation and improving lactobacillus survivability as well as a preparation method and an application thereof, and belongs to the field of deep processing of soybean proteins. The preparation method comprises the following steps: extruding soybean protein at high temperature; damaging a tertiary structure for maintaining the protein through shearing and friction dual functions, thereby enabling the hydrophobic group of the soybean protein to spread; cutting the denatured protein into small molecule peptides by utilizing protease; and performing centrifugal separation, filtering, drying and the like to obtain the soybean peptide. The yield of the soybean peptide reaches up to 72%; and the soybean peptide is low in production cost and can be used for effectively promoting the proliferation of lactobacillus, shortening the fermentation time and improving the survivability of the lactobacillus in a storage period. In addition, the soybean peptide can be applied to fermented dairy products or other foods. Therefore, the soybean peptide is a health food ingredient with high quality.

The invention discloses a method for immobilizing human source arginase-1 through surface display. The method comprises the steps of adding signal peptide and charged polypeptide to the amino terminal of a protein cleavage variant (InaK-N) formed on an ice core, fusing human source arginase-1 into the carboxyl terminal, and designing an HA label at the carboxyl terminal; constructing various recombinant plasmids to convert competent escherichia coli cells, so that different genetic engineering strains are obtained; conducting shake-flask culture on the strains; detecting the display efficiency and enzyme activity of human source arginase-1; selecting the strain with the highest enzyme activity for mass culture, conducting efficient L-arginine conversion, and synthesizing L-ornithine. Human source arginase-1 fused in the protein cleavage variant formed on the ice core is effectively displayed on the surface of an escherichia coli cell, so that human source arginase-1 is immobilized. Compared with an original ice core protein display system, the method has the advantage that the display efficiency and enzyme activity of human source arginase-1 are improved remarkably. Compared with a chitin immobilizing method, the method has the advantages that cost is reduced, process is shortened, and purification steps are simplified.

The present invention relates, e.g., to a method for pre-processing a sample for mass spectral analysis, comprising cleaving proteins in the sample to peptides and immunodepleting highly abundant and / or well-ionizing and / or proteotypic peptides from the sample. Also described are methods for identifying well-ionizing peptides for use in this and other methods; analytic (diagnostic) methods using antibodies against highly ionizable peptides from a protein target of interest; and compositions kits and devices comprising antibodies of the invention.

The invention consists of assay methods, assay kits and antibodies for detecting the polypeptide fragments of dystrophin protein cleavage by enteroviral protease 2A as a result of an enteroviral infection in the heart. The presence of dystrophin cleavage products in the myocytes or blood of a subject is diagnostic for enteroviral infection and myocarditis resulting therefrom.

Invasive remodelling in a mammal may be inhibited by (1) inhibiting or abolishing the protein cleaving action of plasmin and (2) inhibiting or abolishing the protein cleaving action of at least one additional proteolytic enzyme active in invasive remodelling, such as a metalloprotease.

The invention discloses a method for immobilizing human source arginase-1 through surface display. The method comprises the steps of adding signal peptide and charged polypeptide to the amino terminal of a protein cleavage variant (InaK-N) formed on an ice core, fusing human source arginase-1 into the carboxyl terminal, and designing an HA label at the carboxyl terminal; constructing various recombinant plasmids to convert competent escherichia coli cells, so that different genetic engineering strains are obtained; conducting shake-flask culture on the strains; detecting the display efficiency and enzyme activity of human source arginase-1; selecting the strain with the highest enzyme activity for mass culture, conducting efficient L-arginine conversion, and synthesizing L-ornithine. Human source arginase-1 fused in the protein cleavage variant formed on the ice core is effectively displayed on the surface of an escherichia coli cell, so that human source arginase-1 is immobilized. Compared with an original ice core protein display system, the method has the advantage that the display efficiency and enzyme activity of human source arginase-1 are improved remarkably. Compared with a chitin immobilizing method, the method has the advantages that cost is reduced, process is shortened, and purification steps are simplified.

The present invention pertains to field of pharmaceutical chemicals, and relates to thiazole inner salt compounds, preparation methods and uses thereof. Specifically, the present invention relates to a compound of Formula I, hydrates or pharmaceutically acceptable salts thereof. The compound of Formula I of the present invention is a potent cross-linking protein cleavage agent, has a stable structure, good physical and chemical properties, and good pharmacological activities, and is suitable for large scale production to obtain samples with stable, controllable and reliable quality, thereby being suitable for pharmaceutical development.

There are gluten-degrading enzymes found in Rothia species bacteria that are subtilisins that belonging to the S8A family of serine protease family. The Rothia sp. derived subtilisin-like enzymes have the conserved catalytic triad composed of a Ser, His, and Asp residues that is characteristic of the serine protease family. The Rothia subtilisin enzymes are potent at cleaving proline-containing proteins, cleaving the second peptide bond after proline in the XPX1 motif, where X is any amino acid, P is proline and X1 is a hydrophobic amino acid, e.g. the XPQ motif, where Q is glutamine. Embodiments herein provide isolated enzyme compositions and formulations comprising subtilisins gluten-degrading enzyme from a Rothia species bacteria. Also provided herein are methods of treatment of celiac disease or a related disorder, treatment of gluten-containing foodstuff, degrading and / or detoxifying gluten comprising the subtilisins gluten-degrading enzyme and / or compositions.

The invention belongs to the field of biomedicine, and relates to a novel marker-AURKB protein cleavage product for predicting tumor grading and prognosis effects, wherein the novel marker-AURKB protein cleavage product is an AURKB protein cleavage product, and the cutting site is one or a plurality of sites selected from of D75, D76, K85, D186, D238, D255 and D289. The invention also provides a detection method and an evaluation standard with the AURKB protein cleavage product as a tumor marker. The AURKB cleavage product can be used as a tumor grading and prognosis potential marker, and thetargeting inhibitor of the protein cleavage site of the AURKB cleavage product can be used for anti-tumor treatment.