1461 results about "Alanine" patented technology

The invention belongs to the technical field of biochemical engineering, and provides a method for increasing L-carnosine yield of escherichia coli by increasing PRPP supply, and the yield and yield of L-carnosine are remarkably increased by up-regulating expression of a prs gene, increasing PRPP content in cells and promoting synthesis of L-histidine. Experiments show that the yield of the L-carnosine in different recombinant strains is increased by 55.56%-140%, and L-histidine and beta-alanine do not need to be added in the production process.

The invention belongs to the technical field of protein engineering, and discloses a Brazilian sweet protein mutant and application thereof. According to the invention, lysine is used for replacing aspartic acid at the 29th site of Brazilian sweet protein, and / or arginine is used for replacing glutamic acid at the 36th site, and / or alanine is used for replacing aspartic acid at the 50th site, amino acid mutation at the sites is carried out to construct a Brazilian sweet protein mutant, and the Brazilian sweet protein mutant is subjected to heterologous expression in pichia pastoris GS115, so that the Brazilian sweet protein mutant is obtained. And carrying out sweetness performance evaluation on the expressed Brazilian sweet protein mutant. The sweetness property of the double mutant Asp29Lys-Asp50Ala protein is improved by 240% compared with the sweetness property of the Brazilian sweet protein before mutation.

The invention discloses a high-performance carbonyl reductase mutant and application thereof in synthesis of a series of chiral alcohols. The high-performance carbonyl reductase mutant is obtained by performing the following mutations on an amino acid sequence as shown in SEQ ID NO.2: the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine, and the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine; and / or the 100th glycine is mutated into any one of glutamic acid, serine, lysine or asparagine. Compared with a wild type enzyme, the thermal stability and the catalytic activity of the obtained mutant are remarkably improved, particularly, single point mutants Mut-A69N, Mut-G100E and Mut-G100N and a combined mutant Mut-A69N-G100N show excellent relative enzyme activity, thermal stability and substrate tolerance. The mutant has high catalytic activity and stability to various chiral alcohols, and the contradiction that the traditional carbonyl reductase is easy to inactivate at high temperature and the catalytic efficiency is difficult to achieve at the same time is solved. The invention provides an efficient and stable enzyme catalysis tool for green biological preparation of chiral drug intermediates.

The invention relates to the technical field of biological catalysis, and discloses an L379A mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: leucine of the 379th amino acid sequence is mutated into alanine; the enzyme can be applied to RA in-vitro conversion preparation of RI with higher utilization value, the conversion rate is higher than 50%, and the enzyme activity is remarkably improved by 7 times compared with the original enzyme catalytic conversion enzyme activity. The UGT76G1 mutant disclosed by the invention has the advantages that (1) the blank is filled, and a special enzyme catalyst capable of realizing efficient in-vitro synthesis of rebaudioside I (RI) is provided for the first time; 2) efficiency jump: the catalytic conversion rate is greatly increased from original about 7% to more than 50% (increase gt; and 3) stability and reliability: in the cross-scale reaction of 10mL to 5L, the catalyst has stable catalytic performance, shows excellent industrial application potential, and is suitable for popularization and application.

The invention discloses an alanine aminotransferase detection device and method based on a liquid crystal microcavity array, and belongs to the field of optical sensing. The device comprises a functional liquid crystal microcavity array, an excitation optical fiber and a collection optical fiber, the microcavity array is composed of liquid crystal microcavities doped with fluorescent dye and stearic acid, and the multiple microcavities are independently distributed and serve as optical sensing units; the excitation optical fiber is used for synchronously exciting the microcavity to generate an echo wall mode, and the acquisition optical fiber acquires resonance spectrum signals of each channel in real time; the functionalized liquid crystal microcavity is converted into a bipolar configuration from a radial configuration in an enzymatic reaction, echo wall mode spectrum red shift is caused, spectrum shift time is in negative correlation with enzyme concentration, and dual-channel detection is realized by matching with conversion time of a polarized light pattern. According to the detection structure based on the liquid crystal microcavity array provided by the invention, high-flux, real-time and label-free rapid detection on the concentration of alanine aminotransferase can be realized.

The invention provides a method for producing L-phenylalanine, 4-hydroxymandelic acid and / or a PHA material through a one-carbon resource and application of the L-phenylalanine, the 4-hydroxymandelic acid and / or the PHA material. According to the method, a halomonas strain which cannot be directly produced by using a one-carbon resource originally is modified, and a carbon dioxide fixed gene is added, so that recombinant bacteria capable of producing L-phenylalanine and 4-hydroxymandelic acid are constructed, and co-production of extracellular L-phenylalanine, 4-hydroxymandelic acid and other high-added-value compounds and intracellular polyhydroxyalkanoate (PHA) is realized. According to the invention, a more economic, sustainable and high-benefit platform for producing L-phenylalanine, 4-hydroxymandelic acid and PHA is established, and the method plays an important role in further reduction of production cost and improvement of sustainable development.

The invention relates to the technical field of microorganisms, and particularly discloses a recombinant microorganism and application thereof in fermentation production of decarboxylated carnosine. Compared with an original strain, the recombinant microorganism disclosed by the invention has the advantages that the expression of the mdtK gene is enhanced; the starting strain is escherichia coli capable of producing decarboxylated carnosine. When the recombinant microorganism is used for fermentation production, the yield of the decarboxylated carnosine can be increased, L-histidine, histamine or beta-alanine and other precursors do not need to be added in the production process, and an effective novel method is provided for industrial production of the decarboxylated carnosine.

The invention provides a preparation method of 3-boron-L-phenylalanine or a derivative of 3-boron-L-phenylalanine. The preparation method provided by the invention comprises the step of preparing 3-boron-L-phenylalanine as shown in a formula (VI) or a derivative thereof by taking a compound as shown in a formula (III) as a raw material. The method has the advantages of mild reaction conditions, short route, high yield, few byproducts and low cost, and does not need an extremely low temperature condition process or complicated purification steps. # imgabs0 #

The invention belongs to the technical field of skin care product raw materials, and discloses an oligopeptide compound, a preparation method thereof, a beautifying composition and application. The oligopeptide compound has a structural formula of # imgabs0. The oligopeptide compound provided by the invention contains peptide fragments of antioxidant amino acids such as tyrosine (Tyr), beta-alanine (beta-Ala), cysteine (Cys) and proline (Pro), and the amino acids can directly participate in removal of free radicals or form a stable peptide structure to enhance the antioxidant effect; therefore, the oligopeptide compound with anti-oxidation and physiological repair effects is obtained. Meanwhile, a mild Fmoc route is adopted in the preparation method, the condensation reaction time of each step is short, the production period is greatly shortened, raw materials are convenient to obtain, the process is stable, the quality is controllable, the product yield and purity are high, and large-scale production can be achieved.

A boron carrying agent, a preparation method therefor, and a pharmaceutical formulation. The boron carrying agent contains compound 1, N-4-carboxyphenylboronic acid amide-threonine-phenylalanine-phenylalanine-tyrosine-glycine-glycine-serine-arginine-glycine-lysine-arginine-aspartic acid-aspartic acid-phenylalanine-lysine-threonine-glutamic acid-glutamic acid-tyrosine-cysteine, having a molecular formula of C114H158BN30O35S1 and a molecular weight of 2552.4, and further contains compound 2, N-4-carboxyphenylboronic acid amide-arginine-lysine-lysine-lysine-arginine-arginine-glutamine-arginine-arginine-arginine, and / or compound 3, N-4-carboxyphenylboronic acid amide-methionine-alanine-serine-methionine-threonine-glycine-glycine-glutamine-glutamine-methionine-glycine. Compounds 1-3 can serve as a targeted medicament for boron neutron capture therapy used for treating a cerebral glioma and a head and neck tumor.

The invention relates to the technical field of biological catalysis, and discloses an M88A mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: M88A: methionine of the 88th amino acid sequence of UGT76G1 is mutated into alanine; the key conversion rate of RI is greatly increased from 7% to 85% (increased by more than 12 times), and the utilization rate and economical efficiency of raw materials are remarkably improved; the method can be perfectly reproduced under any test scale (10mL, 100mL and 5L), the conversion rate is always anchored to be more than 85%, and incomparable stability and amplification potential are shown.

The application discloses a galactosyltransferase mutant and application thereof in preparation of flavonoid compounds, and belongs to the technical field of enzymology. The application provides a UDP-galactosyltransferase mutant, which is obtained by site-directed mutation of one amino acid in the amino acid sequence of wild-type galactosyltransferase VcUFGT into alanine (A). The effects of a series of mutants H82A, V139A, G141A, P186A, N245A, V282A and S307A are verified in the examples, the mutants can perform enzyme catalysis reaction with quercetin and UDP-galactoside as substrates, and generate flavonoid compound hyperoside, and the specific enzyme activity of the mutants is more than 1.5 times that of the wild type, thereby providing an effective application basis for biosynthesis of flavonoid compounds.

The present invention discloses a pectin methylesterase mutant ΔDdPemA, its encoding gene, preparation method, and application. The pectin methylesterase mutant ΔDdPemA is obtained by mutating the amino acid at position 200 in the center of the substrate binding pocket of the wild-type pectin methylesterase DdPemA from a high-molecular-weight, branched valine to a low-molecular-weight alanine, and by mutating the amino acid at position 339 at the substrate inlet and outlet of the substrate binding pocket from a high-molecular-weight, branched valine to a basic lysine. The amino acid sequence and nucleotide sequence of the wild-type pectin methylesterase DdPemA are SEQ ID NO. 1 and SEQ ID NO. 2, respectively. The mutant enzyme provided by the present invention has significantly improved enzyme activity under weakly acidic conditions, solving the problem of insufficient catalytic activity of the wild-type pectin methylesterase under weakly acidic conditions and creating favorable conditions for the application of the enzyme in the fields of food, textiles, and feed processing.

The present invention discloses a complete medium for culturing DF-1 cells, including DMEM basal medium 13.7g / L, insulin, non-essential amino acids, transferrin, glutathione, ascorbyl phosphate, sodium selenite, ethanolamine, hydrocortisone, and newborn calf serum. Wherein non-essential amino acids include glycine, alanine, proline, serine, and asparagine. A complete medium for culturing DF-1 cells provided by the present invention can well promote the proliferation of DF-1 cells, can achieve the same proliferation effect as high-concentration fetal bovine serum, and is suitable for the adherent culture of DF-1 cells; using low-concentration newborn calf serum, it is possible to greatly avoid the batch differences, unstable culture results, cytotoxicity, and high risk of carrying pathogens brought by the culture medium with high-concentration serum, narrow application range, expensive fetal bovine serum, and high culture cost; the components are simple, the culture medium preparation process is short in time consumption, the culture efficiency is high, the repeatability is good, and it is suitable for batch production.

The invention relates to a mutant based on cytochrome P450BM3 and application of the mutant in chloroaniline biodegradation, and belongs to the field of enzymology. The mutant is obtained by mutating threonine at the 268 site of an amino acid sequence shown in SEQ ID NO.1 into aspartic acid or glutamic acid, mutating alanine at the 328 site into phenylalanine, and mutating alanine at the 328 site into phenylalanine. According to the present invention, the amino acid at the 87 site is mutated into alanine, and the valine at the 78 site is mutated into alanine, such that a variety of mutants such as T268D / A328F, T268E / A328F, T268D / A328F / F87A, T268E / A328F / F87A, T268D / A328F / F87A / V78A and T268E / A328F / F87A / V78A are obtained; according to the present invention, the degradation rate of the mutant on 4-chloroaniline, 2-chloroaniline, 2, 4-dichloroaniline, 3, 4-dichloroaniline and 3, 5-dichloroaniline is achieved; the method has important significance and application value for promoting rapid degradation of chloroaniline pollutants in a water environment and maintaining ecological balance.

The invention provides a method for detecting free amino acids in camellia oleosa seed oil, and establishes a method for detecting the free amino acids in the camellia oleosa seed oil based on ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS), which comprises the following steps: pre-treating various amino acids in the camellia oleosa seed oil by using a non-derivation method; the problems of complicated operation, impurity interference and the like caused by derivatization are avoided, the extraction solvent is environment-friendly and economical, the extraction efficiency is high, and the pretreatment time is greatly shortened; then selecting a proper chromatographic column and a mobile phase, separating a plurality of free amino acids under the condition of not introducing excessive derivatization agents and ion pair reagents, and controlling the collection time to be 12 minutes. The method for detecting the free amino acids in the camellia oleosa seed oil has the characteristics of no need of derivatization treatment, simplicity and convenience in operation, high detection efficiency and good sensitivity and accuracy, and can effectively separate and detect 14 free amino acids such as alanine, phenylalanine and aspartic acid in the camellia oleosa seed oil.

The invention discloses a polypeptide with a whitening effect and a preparation method and application thereof.The polypeptide is obtained from hydrolyzed protein of babylonia areolata, the amino acid sequence of the polypeptide is cysteine-arginine-proline-threonine-cysteine-serine-arginine-leucine-alanine-cysteine, and the amino acid sequence of the polypeptide is cysteine-arginine-proline-threonine-cysteine-serine-arginine-leucine-alanine. The compound can obviously inhibit the generation of melanin in cells and the activity of tyrosinase in vitro, has the characteristics of low toxicity, low irritation, good stability, safety and high efficiency, and can be applied to whitening cosmetics.

The invention relates to a high-carbon biological organic conditioner and application thereof in red soil peanut planting, the high-carbon biological organic conditioner comprises mineral powder, oyster shell powder, zeolite powder, potassium fulvic acid, decomposed cow dung, alanine and glycine according to a mass part ratio of 800: 200: 10: 50: 140: 0.7: 0.5, the content of organic matters in the high-carbon biological organic conditioner is not less than 45 wt.%, the content of humic acid is 20 wt.%, the content of potassium fulvic acid is 20 wt.%, and the content of potassium fulvic acid is 20 wt.%. And bacillus subtilis is contained. By applying the high-carbon biological organic conditioner, the soil quality of the red soil peanut planting area is rapidly improved, the peanut yield is remarkably increased, and an effective technical solution is provided for agricultural sustainable development of the red soil area.

The invention relates to the technical field of biological catalysis, and discloses an L204A mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: L204A: leucine of the 204 amino acid sequence of UGT76G1 mutates into alanine; the high-efficiency in-vitro enzymatic preparation of the rebaudioside I (RI) is realized for the first time, the catalytic efficiency of the rebaudioside I (RI) is improved by more than 7 times (from about 7% to more than or equal to 50%) compared with that of an original enzyme, the high-efficiency performance can be stably maintained under different scales of 10mL to 5L, a solid foundation is laid for industrial application of the RI, and the preparation method is simple, controllable in process condition and suitable for popularization and application.

The invention belongs to the technical field of medicine synthesis, and particularly relates to a preparation method of metaraminol bitartrate. The preparation method comprises the following steps: reacting benzyloxycarbonyl-L-alanine serving as a raw material with dimethylhydroxylamine hydrochloride, then reacting with 3-benzyloxybromobenzene, then carrying out one-step hydrogenation reaction to obtain m-hydroxylamine, and finally salifying to obtain the metaraminol bitartrate. The method adopts a one-step hydrogenation method to simultaneously realize dual effects of reduction and deprotection, reduces operation steps and material consumption, saves material cost, and reduces generation of reaction wastes; in the preparation process, reaction conditions are mild, safety and reliability are achieved, operation is easy, and the obtained target product is high in yield, good in selectivity and suitable for large-scale production.

The invention relates to the field of plant molecular biology and forest genetic engineering, and particularly provides a PagRAP2.3 protein point mutant and application thereof in drought resistance of poplar. The mutant PagRAP2.3 MA is obtained by mutating methionine at the first site and cysteine at the second site of a wild type PagRAP2.3 protein into methionine and alanine. The invention further discloses a preparation method of the mutant PagRAP2.3. An expression vector containing the PagRAP2.3 MA gene is constructed, poplar 84K is transformed through an agrobacterium-mediated method, and a transgenic line with stable expression is obtained. Functional verification results show that overexpression of PagRAP2.3 MA can significantly increase the plant height of the poplar and promote plant growth, but the sensitivity to moisture is enhanced under drought stress. The mutant can be used for regulating and controlling the growth and development of forest trees and evaluating the drought resistance, and has a forestry breeding application prospect.

The invention belongs to the field of metabolic engineering, and discloses a genetically engineered bacterium of high-yield beta-alanine as well as a construction method and application of the genetically engineered bacterium. The genetically engineered bacterium takes escherichia coli W3110 as an original strain, and is obtained by performing the following gene editing on a genome of the escherichia coli W3110, the genetically engineered bacterium does not express proteins such as lactose operon repressor protein, pyruvate dehydrogenase, acetokinase and the like; protein such as aspartic acid-alpha-decarboxylase, phosphoenolpyruvate carboxylase, pyruvate carboxylase and the like is overexpressed; the phosphoenolpyruvate carboxykinase is replaced by phosphoenolpyruvate carboxykinase from Mannheim succinic acid producing bacteria. The genetically engineered bacterium BA-17 for high yield of beta-alanine, which is constructed by the invention, is fermented in a 5L fermentation tank for 60 hours, the yield of beta-alanine reaches 126.7 g / L, the conversion rate reaches 60.3%, and the production intensity reaches 2.11 g / L / h.

The invention relates to a TaCBL4 mediated TaSOS1 phosphorylation regulation and control site in wheat and an application of the TaCBL4 mediated TaSOS1 phosphorylation regulation and control site. The TaSOS1 phosphorylation regulation and control site is Ser978-Ser1126 / Ser1128 (S978-DSPS); the phosphorylation regulation and control site of the TaSOS1 is S978-DSPS, and serine at the site 978 of the TaSOS1-DAA (S1126AS1128A) is mutated into alanine. The TaSOS1 in the wheat is from a chromosome LOC778390, NC057800.1 (13146069..13157356) of the 3A of the common wheat, and the TaSOS1 in the wheat is from a chromosome NC057800.1 (13146069..13157356). The invention also relates to an application of the TaCBL4 mediated TaSOS1 phosphorylation regulation site Ser978-Ser126 / Ser128 (S978-DSPS) in the wheat as a molecular marker for detecting the salt tolerance of the wheat, and also relates to an application of the TaCBL4 mediated TaSOS1 phosphorylation regulation site. The site is applied to the aspects of wheat salt tolerance improvement and assisted breeding.

The disclosure relates to double halogenated phenylalanine derivatives, which can be radiolabeled with PET or SPECT radioisotopes, and their use in treating and / or imaging cancer.

Provided herein is a method for the screening of patients with at-risk MASH (metabolic dysfunction-associated steatohepatitis, formerly named nonalcoholic steatohepatitis or NASH). The combination of levels of five circulating markers, i.e. alanine aminotransferase (ALAT), aspartate transaminase (ASAT), platelets, hsa-miR-34a and YKL-40 in a subject, and eventually the age and gender of said subject, allows to accurately identify non-cirrhotic at-risk MASH. The information obtained from the levels of these markers also allows to screen a subject as being eligible to liver biopsy and / or to classify a subject as a receiver or non-receiver of a treatment of MASH and / or to classify a subject as a responder or non-responder of a treatment of MASH.

The invention provides a penicillin G acylase AxPGA mutant, an expression plasmid, a genetically engineered bacterium and application, and belongs to the technical field of biocatalysts. The mutant is obtained by mutation of any one or more of the following sites of an amino acid sequence as shown in SEQ ID NO: 1: (1) methionine at the 103rd site is substituted by cysteine, (2) tyrosine at the 424th site is substituted by phenylalanine, (3) tyrosine at the 442nd site is substituted by phenylalanine, and (4) tyrosine at the 451st site is substituted by alanine. The obtained penicillin G acylase AxPGA mutant is relatively high in enzyme activity and can be applied to high-conversion-rate and high-yield synthesis of beta-lactam antibiotics such as benicillin and amoxicillin.

The present application relates to a pyridoxal kinase mutant, a recombinant expression vector and a microbial cell and their applications, and belongs to the technical field of biological catalysis. In order to solve the problem of low product concentration in existing enzyme catalysis, a pyridoxal kinase mutant is provided, the amino acid sequence is selected from the amino acid sequence shown in SEQ ID NO. 1, the lysine at position 229 is mutated to alanine, phenylalanine, methionine, arginine, threonine, histidine, serine, tyrosine, valine, leucine, isoleucine, proline, asparagine, aspartic acid or glutamic acid; the pyridoxal kinase mutant is used for catalyzing pyridoxal to synthesize pyridoxal phosphate, and a recombinant expression vector and a microbial cell can be further formed. The present application has good enzyme activity, high product conversion rate, high concentration of pyridoxal phosphate obtained, and the concentration of the product catalyzed by the wild-type pyridoxal kinase to phosphorylate pyridoxal is obviously improved.

The invention relates to the technical field of concealed project acceptance, and discloses an alpine region bluegrass cold-resistant growth-promoting nutrient solution and an application method thereof.The nutrient solution is composed of main nutrient elements such as nitrogen, phosphorus and potassium and microelements such as iron, manganese, zinc, copper and boron, and amino acid substances such as glycine, alanine and proline are added; therefore, comprehensive and balanced nutrition support is provided. Through a scientific fertilization strategy, including three stages of seed treatment, seedling stage management and growth stage management, and in combination with a drip irrigation system and a foliage spraying technology, efficient utilization of nutrients and healthy growth of plants are ensured. According to the method, the growth speed and biomass of the bluegrass are remarkably increased, the soil structure is improved, the stress resistance of crops is enhanced, the nutrient utilization efficiency is improved, and finally the product quality and market value are improved; the comprehensive benefits are beneficial to promoting the sustainable development of agriculture in alpine regions.

The present disclosure relates to a protein-based article comprising a film having a thickness of about 0.1 μm to about 10 mm and comprising a crosslinked network of partially ordered polypeptides, wherein each partially ordered polypeptide independently comprises a plurality of disordered domains and a plurality of ordered domains, wherein each disordered domain independently comprises a PG or GP motif and each ordered domain independently comprises a polyalanine motif or a polyproline motif.

The invention belongs to the technical field of biological medicine, and particularly relates to application of phenylalanine in evaluating Kawasaki disease and treating effect thereof and application of a phenylalanine inhibitor in treating Kawasaki disease. According to serum non-targeted metabonomics analysis and verification of KD children and IVIG treated KD children, phenylalanine is highly expressed in KD children, and phenylalanine is remarkably reduced after IVIG treatment of KD and tends to healthy children. The phenylalanine can be used as a serological marker for evaluating the Kawasaki disease treatment effect and diagnosing IVIG second-line treatment, and is high in specificity and sensitivity. After the phenylalanine inhibitor is administered to a KD model mouse, the content of phenylalanine in serum is remarkably reduced and is consistent with the trend in serum of the KD mouse treated by IVIG, myrica tongues are remarkably relieved, arterial dilatation is slowed down, and expression of inflammatory factors is reduced. The phenylalanine inhibitor has the effects of treating Kawasaki disease, improving myrica rubra tongue and slowing down arterial dilatation.