18 results about "Deamidation" patented technology

The invention belongs to the technical field of food, and provides a special enzyme composition for infant soybean milk powder and soybean milk powder thereof. A three-stage directional enzymolysis technology is adopted, the three-stage directional enzymolysis technology comprises glutamine transaminase deamidation pretreatment, bacillus subtilis protease-trypsin-papain first-stage hydrolysis and aminopeptidase-phytase-beta-glucosidase second-stage hydrolysis, and conductivity control, carbon dioxide ventilation in-situ complexation and spray drying processes are combined. The free amino nitrogen of the product is increased by more than or equal to 20%, the proportion of 200-1500Da peptide fragments is more than or equal to 70%, the median particle size is 50-180 microns, the water activity is less than or equal to 0.30, the instant dissolving time is less than or equal to 30 seconds at 25 DEG C under the water hardness of 15-200ppm, the settling rate is less than or equal to 3% after standing for 30 minutes, and the zeta potential is-10 to-25mV. The palatability contradiction between deep hydrolysis and bitterness inhibition of the bean-based infant formula powder, the brewing contradiction between high-calcium reinforcement and instant stability and the process controllability contradiction between three-stage enzymolysis and ionic strength accumulation are effectively solved, and the bean-based infant formula powder has wide application value in the fields of bean-based infant formula food and vegetable protein nutritional products.

This invention relates to the field of lyophilized formulation technology, specifically disclosing an esupagglutide α-nano-lyophilized micelle and its preparation method. The micelles of this invention utilize polylactic-co-hydroxyacetic acid copolymer and sodium phosphatidylglycerol as micelle carriers, with arginine and cysteine ​​providing branching synergistic effects. Homogenization via film formation and low-temperature lyophilization yield lyophilized nano-micelle powder. The nano-micelle powder reduces protein oxidative decomposition during lyophilization, decreases impurity fragments, and reduces various non-fucose glycosylation, basic components (succinimide, methionine oxidation products), N-terminal deletion, Asn deamidation, and Met and Trp residue oxidation impurities that affect product quality. Product quality analysis and animal experiments after reconstitution show good resistance to impurities and degradation risk. The reconstituted esupagglutide α-nano-micelle system exhibits better stability and sustained-release properties, enhancing the hypoglycemic sustained-release effect 72 hours after injection, significantly improving upon conventional non-micelle formulations.

Methods of differentiating and quantifying modifications in the tau protein in bio-fluids to detect, classify, and treat a plurality of tauopathies are disclosed. The disclosed methods include liquid chromatographic mass spectrometric analyses on isolated tau protein fragments to identify and quantify deamidated or isomerized asparagines or aspartic acids indicative of a neuropathology associated with a tauopathy.

The invention relates to a Chryseobacterium-derived protein glutaminase PG3, a coding gene and an application thereof, and belongs to the technical field of biological genetic engineering. The amino acid sequence of the protein glutaminase PG3 is as shown in SEQ ID No. 1, and the cDNA sequence of the coding gene of the protein glutaminase PG3 is as shown in SEQ ID No. 2. A large amount of protein glutaminase PG3 from Chryseobacterium is prepared through an Escherichia coli expression system, and the protein glutaminase is used for carrying out enzymatic deamidation modification on the spotted silver carp myofibrillar protein PG3, so that the solubility of the spotted silver carp myofibrillar protein under a salt-free system condition is remarkably improved. The invention provides an important tool enzyme for protein deamidation modification, and lays a theoretical foundation for development of low-salt fish protein processed products.

The invention provides a protein glutaminase mutant with improved thermal stability and application thereof, and relates to the technical field of enzyme engineering. According to the invention, a female parent sequence of protein glutaminase is modified, the modification comprises saturated mutation and combinatorial mutation of 30th serine and 108th serine with the female parent sequence such as SEQ ID NO.1, the relative enzyme activity of the screened mutant and the residual enzyme activity after treatment at 60 DEG C are obviously improved compared with those of a wild type, and the mutant shows higher thermal stability. The residual enzyme activity of the combined mutant S30F / S108Q at the temperature of 60 DEG C is improved by 436.4% compared with that of a wild type, the deamidation degree of the combined mutant S30F / S108Q to soybean protein at the temperature of 55 DEG C is improved by 18.5% compared with that of the wild type, the problems that in the prior art, the thermal stability of protein glutaminase is poor, and industrial production and application cannot be met are solved, and the combined mutant S30F / S108Q has good application prospects in the fields of food processing, feed production and the like.

The invention provides a protein glutaminase mutant with synchronously improved enzyme activity and thermal stability and application of the protein glutaminase mutant, and belongs to the field of gene engineering and enzyme engineering. According to the invention, a series of mutants MT1-MT6 are obtained by carrying out molecular modification on a coding gene of protein glutaminase PG3 from Chryseobacterium sp. Compared with a wild type, the mutant MT6 has the advantages that the optimal catalytic temperature of the mutant MT6 is increased by 5 DEG C, the specific activity and the specific activity t65 DEG C 1 / 2 are 106.1 U / mg and 76.7 min respectively and are 2.69 times and 2.99 times of the specific activity t65 DEG C 1 / 2 of the wild type, the purpose of simultaneously improving the catalytic activity and the thermal stability of the protein glutaminase PG3 is achieved, and the application potential of the protein glutaminase in the industrial field is expanded. In addition, the mutant can significantly improve the foamability and stability of the myofibrillar protein of the spotted silver carp, and provides a potential enzyme resource for enhancing the functional characteristics of the protein through enzymatic deamidation modification.

The invention provides a protein glutaminase mutant as well as a coding gene and application thereof, and belongs to the field of gene engineering and enzyme engineering. According to the invention, a series of mutants MT1-MT8 are obtained by carrying out molecular modification on a coding gene of chitophage protein glutaminase PG5. Compared with a wild type, the mutant has the advantages that the optimal catalytic temperature is increased by 5 DEG C, the specific activity and t55 DEG C 1 / 2 are 31.1 U / mg and 216.2 min respectively and are 2.99 times and 3.57 times that of the wild type, and the application potential of protein glutaminase in the industrial field is expanded. Besides, the mutant can significantly improve dissolution of the myofibrillar protein of the spotted silver carp under the condition of a salt-free system, provides a potential enzyme resource for enzymatic deamidation modification and enhancement of protein functional characteristics, and has a wide market application prospect.

The invention relates to chitophage protein glutaminase PG5, a coding gene and application of the chitophage protein glutaminase PG5, and belongs to the technical field of biological genetic engineering. The amino acid sequence of the protein glutaminase PG5 is as shown in SEQ ID No. 1, and the cDNA sequence of the coding gene of the protein glutaminase PG5 is as shown in SEQ ID No. 2. A large amount of chitophage-derived protein glutaminase PG5 is prepared through an escherichia coli expression system, and the protein glutaminase PG5 is used for carrying out enzymatic deamidation modification on the myofibrillar protein of the spotted silver carp, so that the thermal reversible protein gel is successfully prepared in a salt-free system. An important tool enzyme is provided for protein deamidation modification, unprecedented flexibility is provided for processing adaptability and cold-chain storage and transportation of fish protein gel products, and the application range of the fish protein gel products in food design is greatly expanded.

The invention belongs to the technical field of aquatic product processing, and provides minced fillet soft gel and a preparation method thereof. The minced fillet soft gel is prepared from the following raw materials in parts by weight: 96-99 parts of minced fillet, 0.1-0.3 part of protein glutaminase, 1-2 parts of table salt and 0.5-1 part of composite phosphate. Protein glutaminase is added in the preparation process of the minced fillet gel, so that the hardness of the gel can be remarkably reduced, the moisture retention capability of the gel can be greatly improved, and the requirements of the special soft minced fillet gel for patients with dysphagia on texture and moisture are met; meanwhile, ultrasonic-assisted deamidation treatment is introduced, so that the working efficiency of the enzyme can be improved, the enzyme addition amount can be reduced to save the production cost, the gel hardness and the gel strength of the minced fillet can be further reduced, the water holding capacity is enhanced, the digestion characteristic of the minced fillet is improved, and finally, an easy-to-swallow food rich in high-quality protein is provided for people with dysphagia.

To provide compositions comprising AAV-based constructs for delivery of heterologous molecules which have stable receptor binding and / or stable capsid, avoid neutralizing antibodies and / or retain purity during storage.SOLUTION: A recombinant adeno-associated virus (rAAV) vector comprises an AAV capsid having a heterogeneous population of vp1 proteins, a heterogeneous population of vp2 protein and a heterogeneous population of vp3 proteins. The capsid contains modified amino acids as compared to the encoded VP1 amino acid sequence, the capsid containing highly deamidated asparagine residues at asparagine-glycine pair, and further comprising multiple other, less deamidated asparagine and optionally glutamine residues.SELECTED DRAWING: Figure 1A

The present invention provides deamidase compositions comprising a deamidase inhibitor, wherein the deamidase exhibits less self-deamidation and / or modification to other enzymes after storage.

A recombinant adeno-associated virus (rAAV) vector comprising an AAV capsid having a heterogeneous population of vp1 proteins, a heterogeneous population of vp2 protein and a heterogeneous population of vp3 proteins. The capsid contains modified amino acids as compared to the encoded VP1 amino acid sequence, the capsid containing highly deamidated asparagine residues at asparagine-glycine pair, and further comprising multiple other, less deamidated asparagine and optionally glutamine residues.

The invention belongs to the technical field of biology, and discloses an artificially modified cephalosporin C acylase mutant and application thereof. The mutant is obtained by carrying out molecular evolution on wild-type enzyme through a DNA shuffling technology, the amino acid sequence of the mutant is shown as SEQ ID NO: 1, and compared with the wild-type enzyme, the mutant has remarkably improved catalytic activity and can efficiently catalyze cephalosporin C deamidation to generate 7-aminocephalosporanic acid. The invention also discloses a nucleic acid molecule for coding the acylase, a recombinant vector and a recombinant host cell containing the nucleic acid molecule, and application of the acylase or the recombinant host in production of 7-ACA by using cephalosporin C as a substrate.

The invention discloses flavor-improved pleurotus eryngii protein and a preparation method thereof, and belongs to the technical field of food processing. The method comprises the following steps: (1) crushing and sieving dried pleurotus eryngii to obtain pleurotus eryngii powder; (2) carrying out degreasing treatment on the pleurotus eryngii powder by using normal hexane so as to remove fat-derived peculiar smell precursor substances; (3) mixing the degreased pleurotus eryngii powder with water, extracting protein under an alkaline condition, and centrifuging to obtain supernate; (4) adjusting the pH value of the supernate to be neutral, adding glutaminase (PG) to carry out an enzymolysis reaction, and modifying a protein structure through a deamidation effect; and (5) inactivating the enzymatic hydrolysate, adjusting to an isoelectric point to precipitate protein, washing, neutralizing and drying to obtain a final product. The method has the remarkable advantages that a deamidase modification process is innovatively integrated into a protein extraction link, and structural modification, flavor improvement and extraction and purification are integrally completed through the synergistic effect of alkali extraction, acid precipitation and enzymolysis. The method effectively overcomes the defects that the inherent peculiar smell of the traditional pleurotus eryngii protein is obvious, and the processing performance (such as water solubility) is poor, the obtained product is pure in flavor, the functional characteristics are remarkably improved, and a new way is opened up for high-value application of the pleurotus eryngii protein in various healthy foods.

This invention provides a liquid enzyme formulation of a protein deamidation enzyme with excellent activity stability. [Solution] A liquid enzyme preparation containing a protein deamidation enzyme and 30% w / v or more of sorbitol, with a pH of 5.5 or higher.

Rapid comparability assessment of asparagine or glutamine deamidation of therapeutic proteins, peptides other modalities against a reference standard using two trace two-dimensional correlation spectroscopy. Asynchronous plots are generated providing information of the abundance of the components under evaluation. The method is valid for an array of protein samples providing an estimate of the extent of deamidation. The results of which are orthogonal to HPLC cation exchange, thus validating the existence of the deamidated species and if aggregate is present. This rapid method run time is only 10 minutes for up to 21 samples in their formulation condition.

The invention discloses an aroma enhancing method for deamidating micelle casein based on protein glutaminase. The method comprises the following steps: adjusting the pH value of a micelle casein system to 6.0-8.0, reacting the micelle casein system with protein glutaminase at 45-55 DEG C for 5-40 minutes, and then carrying out heat treatment to terminate the reaction. The deamidation treatment can obviously improve the deamidation degree of micelle casein from about 4% to 48% or above, and glutamine residues are converted into glutamic acid, so that the physicochemical properties of protein are effectively changed, the binding capacity of the protein and flavor molecules is weakened, and the release and retention of fragrance are promoted. Experiments show that the headspace concentration of the total volatile aroma substances of the treated sample is remarkably increased, the aroma profile is optimized, specifically, the relative proportion of esters and lactones with sweet aroma, frankincense and fruit aroma is greatly increased, and meanwhile, the unpleasant odor is weakened. The method is simple in process, mild in condition and suitable for flavor quality improvement of various dairy products.

Characteristics of proteins, peptides, and / or peptoids can be determined via two-dimensional correlation spectroscopy and / or two-dimensional co-distribution spectroscopies. Spectral data of the proteins, peptides, and / or peptoids can be obtained with respect to an applied stress, such as thermal stress. Two-dimensional correlation spectroscopy can be used to generate two-dimensional synchronous and asynchronous plots. The asynchronous plot provides enhanced resolution and the sequential order of molecular events that occur as a function of the applied stress. Peaks may be identified in the asynchronous plot, and correlation of peaks that exhibit out-of-phase intensity changes can be used to determine the existence and extent of deamidation events.