174 results about "Protease digestion" patented technology

Methods, compositions, kits, and apparatus are provided wherein the aminoacyl-tRNA synthetase system is used to analyze amino acids. The method allows very small devices for quantitative or semi-quantitative analysis of the amino acids in samples or in sequential or complete proteolytic digestions. The methods can be readily applied to the detection and/or quantitation of one or more primary amino acids by using cognate aminoacyl-tRNA synthetase and cognate tRNA. The basis of the method is that each of the 20 synthetases and/or a tRNA specific for a different amino acid is separated spatially or differentially labeled. The reactions catalyzed by all 20 synthetases may be monitored simultaneously, or nearly simultaneously, or in parallel. Each separately positioned synthetase or tRNA will signal its cognate amino acid. The synthetase reactions can be monitored using continuous spectroscopic assays. Alternatively, since elongation factor Tu:GTP (EF-Tu:GTP) specifically binds all AA-tRNAs, the aminoacylation reactions catalyzed by the synthetases can be monitored using ligand assays. Microarrays and microsensors for amino acid analysis are provided. Additionally, amino acid analysis devices are integrated with protease digestions to produce miniaturized enzymatic sequenators capable of generating either N- or C-terminal sequence and composition data for a protein or peptide. The possibility of parallel processing of many samples in an automated manner is discussed.

A process for preparing collagen matrix with heterogeneous bone, used as the bone repairing material and the extracellular matrix of bone tissue engineering, includes such steps as treating ox bone or pig bone, defatting, partial decalcifying, removing non-collagen, proteinas digesting, disinfecting and packing. It has better porosity and pore canal structure.

The present invention provides for novel reagents whose fluorescence increases in the presence of particular proteases. The reagents comprise a characteristically folded peptide backbone each end of which is conjugated to a fluorophore. When the folded peptide is cleaved, as by digestion with a protease, the fluorophores provide a high intensity fluorescent signal at a visible wavelength. Because of their high fluorescence signal in the visible wavelengths, these protease indicators are particularly well suited for detection of protease activity in biological samples, in particular in frozen tissue sections. Thus this invention also provides for methods of detecting protease activity in situ in frozen sections.

An adjustable, low mass-to-charge (m/z) filter is disclosed employing electrospray ionization to block ions associated with unwanted low m/z species from entering the mass spectrometer and contributing their space charge to down-stream ion accumulation steps. The low-mass filter is made by using an adjustable potential energy barrier from the conductance limiting terminal electrode of an electrodynamic ion funnel, which prohibits species with higher ion mobilities from being transmitted. The filter provides a linear voltage adjustment of low-mass filtering from m/z values from about 50 to about 500. Mass filtering above m/z 500 can also be performed; however, higher m/z species are attenuated. The mass filter was evaluated with a liquid chromatography-mass spectrometry analysis of an albumin tryptic digest and resulted in the ability to block low-mass, “background” ions which account for 40-70% of the total ion current from the ESI source during peak elution.

It is intended to provide a soybean protein material which is excellent in solubility, stability, emulsifying properties and gel-forming properties under acidic conditions and thus advantageously usable in acidic foods, its production process, and acidic foods using the soybean protein material. A solution containing soybean protein is subjected to a treatment for eliminating or inactivating polyanionic substances contained therein and/or adding a polycationic substance and then heated at above 100° C. under acidic conditions. Thus, a soybean protein having a high solubility under acidic conditions and thus being appropriately usable in acidic foods can be obtained. By using this protein, protein foods in an acidic region can be provided. Further, by combining the above-described treatment with a protease-digestion treatment, a soybean protein hydrolysate having a high solubility in an acidic region can be efficiently obtained.

The invention provides a method for soluble expression of recombinant protein of a human brain natriuretic peptide (Human Brain Natriuretic Peptide, hBNP). The method comprises the following steps: 1) obtaining a recombinant gene, namely obtaining the recombinant gene His-DsbAmut-BNP of expressing the recombinant protein of the human brain natriuretic peptide, wherein the sequence of the recombinant gene comprises a purified tag gene sequence, a molecular chaperone protein gene sequence, a protease recognition site sequence and a human brain natriuretic peptide sequence, which are sequentially arranged along the direction from 5' to 3'; 2) obtaining recombinant plasmids, namely inserting the recombinant gene obtained in the previous step into a carrier vector, so as to obtain the recombinant plasmids containing the recombinant gene; 3) obtaining genetically engineered bacterium, transferring the recombinant plasmids obtained in the previous step into host cells to obtain the genetically engineered bacterium; 4) expressing exogenous genes, fermenting the genetically engineered bacterium, and expressing fusion protein containing the human brain natriuretic peptide; 5) purifying target protein, splitting thallus, collecting fusion protein, removing molecular chaperone and carrying out chromatographic purification by protease digestion, so as to obtain the recombinant protein of the human brain natriuretic peptide.

A harmless cancer vaccine is made from cancer cells with extracellular proteins including self-recognition molecular patterns being digested by a proteinase. The cancer vaccine is used to vaccinate an individual to induce immune responses against cancer cells systemically. Cancer cells become harmless when they are digested by Tumorase™. Some proteinases including trypsin cannot kill cancer cells completely and treated cancer cells need to be further processed in order to be harmless and effective. Cancer cells may be from tissue-cultured human or animal cancer cell lines or cancer patients directly. Cancer vaccine vaccinated individuals produce cancer vaccine specific immune responses against cancer cells. Immune response components may be isolated and used to fight against cancer for a cancer patient with a suppressed immune system. Cancer vaccine specific immune components may include cancer vaccine specific polyclonal antibodies, B-cells, T-cells, natural killer cells, monocytes, macrophages and other lymphocytes.

The invention relates to a serum-free medium of a human amniotic epithelial stem cell and a culture method thereof. The serum-free medium is formed by adding a human epidermal growth factor, human transferring, human insulin, sodium selenite, alanyl-L-glutamine dipeptide, alanine, asparaginate, aspartic acid, glutamic acid, glycine, proline and serine to a DMEM/F12 basic medium. The culture method comprises the steps of digesting 2.5g/L of trypsin for a human amniotic membrane, obtaining the human amniotic epithelial stem cell and filtering to prepare a single cell suspension; putting the human amniotic epithelial stem cell into a CO2 incubator of which the saturated humidity and the volume fraction are 5% at 37 DEG C through the serum-free medium under a serum-free condition and achieving growth and amplification of the amniotic epithelial stem cell through liquid exchange and subculture under the serum-free culture condition, the serum-free medium has the characteristics of stem cells, and is free of other animal sources, wide in source and free of ethical restriction.

An immunoactive substance extracted from tuna fish head and a preparation method thereof are provided. The method comprises the following steps: pretreatment, washing, crashing, protease digestion, hydrolysis with neutral protease and papain, oil-water separation, hydrolysate centrifugation, oil-water separation of filtrate, separation of protein hydrolysate and fish oil, fractional separation, and separation of protein hydrolysate by using ultrafiltration membrane, to obtain immunoactive substance of tuna fish head. The invention utilizes two proteases to hydrolyze proteins of tuna fish head and centrifugally separates peptide-rich protein hydrolysate with immunological activity. The protein hydrolysate can be further processed to oral liquid, capsules and tablets. Furthermore, the invention produces fish oil rich in polyunsaturated fatty acids, thereby realizing the comprehensive and high-efficiency utilization of tuna fish head. The immunoactive substance of tuna fish head can significantly improve humoral immunity and nonspecific immunity in mice and enhance the cellular immune function of mice.

Compositions and methods for treating or preventing, for example, overweight or obesity are provided. Compositions provided comprise zinc-charged, protease digested serum or milk proteins. Compositions are administered in a therapeutically effective amount to treat or prevent, for example, overweight or obesity.

An object of the present invention is to elucidate a collagen peptide effective for causing dipeptides or tripeptides serving as the active component to enter the blood, and thus to reduce the required intake thereof. According to the present invention, a collagen peptide composition obtained by digesting collagen or gelatin with protease is provided, wherein:

(a) the ratio of hydroxyproline to total of amino acid residues at the second position from the N terminus of the peptides in the composition is 2 mol % or more and 20 mol % or less, and the ratio of glycine to total of amino acid residues at the third position from the N terminus of the peptides in the composition is 20 mol % or more and 50 mol % or less; and

(b) the average molecular weight is 500 or more and 2000 or less.

The invention discloses a method for culturing and amplifying odontogenic epithelial cells, and belongs to the technical field of cell culture. The method for culturing and amplifying the odontogenic epithelial cells of the invention comprises the steps of obtaining and culturing primary epithelial cells and amplifying the epithelial cells, wherein the primary culture comprises the steps of digesting odontogenic chyle-shaped tissues by using mixed enzyme digestive juice consisting of dispersing enzyme, I-type collagenase and DNA enzyme, collecting cells and culturing; and the mixed enzyme comprises the dispersing enzyme, the I-type collagenase and the DNA enzyme; and sub-culturing comprises the steps of digesting the cells by combining a cell scraper scrapping method and a 0.025 to 0.25 percent trypsin digestive juice, suspending the cells again with a culture medium and culturing. By the method, the cells are sub-cultured for 2 to 3 times to form a great number of purified odontogenic epithelial cells which are identified to be epithelial cells by an epithelial cell expression marker CK14. The method solves the problem of difficulty in culturing the odontogenic epithelial cells, and a great number of stable and purified odontogenic epithelial cells are obtained and the source of the epithelial cells is provided for the teeth development and regeneration research.

An object of the present invention is to elucidate a collagen peptide composed of oligopeptides having ability to enter the blood higher than that of conventional collagen peptides and thus to provide a food or beverage mixed with the collagen peptide. The present invention provides a collagen peptide composition obtainable by digesting a collagen or gelatin with protease, which comprises 70% to 100% by weight of peptides with a molecular weight 500 or more to 3000 or less, less than 10% by weight of peptides with a molecular weight of less than 500, and less than 20% by weight of peptides with a molecular weight of more than 3000, based on the total weight of the composition, wherein the ratio of N-terminal glycine residues to total of the N-terminal amino acid residues of the peptides in the composition is 33 mol % or more to 65 mol % or less.

The present invention relates to follicular stem cell originated from human hair and its amplifying preparation process, and belongs to the field of medical preparation and human cell culture technology. The present invention adopts improved two-step protease digesting method to amplify follicular stem cell originated from human hair and obtains follicular stem cell with active expression of beta-integrin and keratin 19 in an optimized follicular stem cell preparing environment. The optimized micro environment endows follicular stem cell with fast amplification, antisenile characteristic, the epidermic cell-like, fibroblst-like and hair bulb tissue-like structure or functional expression. The present invention makes it possible to provide sufficient seed cell sources for the fast repair and functional reconstruction of skin defect.

The invention relates to a method and a reagent for improving the rate of extraction of the DNAs of castoff cells in a case trace sample. Due to the problems of trace amount of case sample, keratinization of cells, multiple polymerase chain reaction (PCR) complex amplification of 16 short tandem repeat (STR) loci and the like, the extraction of the DNAs of castoff cells has long been a difficult point in forensic medicine. According to researches, the combination of pronase digestion, bath at 70 to 100 DEG C and polyethylene glycol(PEG)-ethanol magnetic bead combined system can help to effectively extract trace DNAs and to obtain DNA fragments with a proper length, so that the need of complex amplification of the 16 STR loci in case detection can be satisfied and the success rate of the case detection is improved. The pronase digestion and warm bath allow the castoff cells to release DNAs effectively and ensures the relatively complete structure of the DNAs and the easy combination of the DNAs with the magnetic beads in the PEG-ethanol system. The use of the PEG-ethanol combined system promotes the high-efficiency DNA adsorption of the magnetic beads, ensures the relatively complete structure of the DNA and ensures that DNA fragments with proper length can be obtained to satisfy the need for the complex amplification of the 16 STR loci in case detection.

The invention discloses a bactericidal and anti-itching medicated soap and a preparation method thereof. The medicated soap achieves bactericidal and bacteriostatic effects by fixing ozone to ozone salt and utilizing the efficient bactericidal action of the ozone; meanwhile, itching caused by skin allergy is reduced through a variety of Chinese herbal medicines and essential oil with the anti-itching effect; in addition, through mutual cooperation with a giant salamander mucus protein extract, horse oil, badger fat and ambergris, skin is nourished and itching and cracking caused by dryness areprevented. Through adoption of a formula of a neutral soap and supplemented by a foaming agent, during using, the medicated soap is smooth, delicate, non-irritant to the skin and good in skin friendliness; in addition, through addition of large-grained sea salt, the hardness and the plasticity of the medicated soap can be better and industrial production is more facilitated. Through protease digestion and use of natural plant raw materials during preparation, the safer factor of the medicated soap is higher and allergic risks are eliminated.

The present invention provides for novel reagents whose fluorescence increases in the presence of particular proteases. The reagents comprise a characteristically folded peptide backbone conjugated to two fluorophores such that the fluorophores are located opposite sides of a cleavage site. When the folded peptide is cleaved, as by digestion with a protease, the fluorophores provide a high intensity fluorescent signal at a visible wavelength. Because of their high specificity and their high fluorescence signal in the visible wavelengths, these protease indicators are particularly well suited for detection of protease activity in biological samples, in particular in frozen tissue sections. Thus this invention also provides for methods of detecting protease activity in situ in frozen sections.

The invention discloses a cryopreservation method of umbilical cord mesenchymal stem cells, which comprises the following steps: (1) taking mesenchymal stem cells, resuspending the mesenchymal stem cells with a culture medium, repaving the mesenchymal stem cells into a culture bottle, and harvesting the mesenchymal stem cells when the fusion of the cells in the culture bottle reaches 90% or above;(2) pouring out the culture medium in the culture bottle, conducting washing, adding trypsin for digestion, and adding mixed normal saline to terminate digestion after the digestion is finished; (3)transferring the digested cells into a centrifuge tube, carrying out centrifugal treatment, discarding the supernatant, re-suspending the precipitate, carrying out centrifugation again, and discardingthe supernatant to obtain mesenchymal stem cells; and (4) adding the mesenchymal stem cells into a cryopreservation liquid, conducting resuspending, conducting sub-packaging in cryopreservation tubes, carrying out gradient cooling, conducting transferring to a cryogenic refrigerator, and completing cryopreservation. According to the cryopreservation method of the umbilical cord mesenchymal stem cells, the used cryopreservation liquid has a good cryopreservation effect on the umbilical cord mesenchymal stem cells, is efficient, does not contain any animal-derived component and can be directlyused as MSCs cryopreservation liquid for clinical infusion.