876 results about "Phenylalanine" patented technology

The invention discloses a formate dehydrogenase mutant and application of the formate dehydrogenase mutant in catalysis of carbon dioxide reduction, the 223 arginine (Arg) of an amino acid sequence of formate dehydrogenase PsFDH48 derived from Paracoccus sp. MKU1 is mutated into proline (Pro) or the 242 proline (Pro) is mutated into phenylalanine (Phe) through a site-specific mutagenesis technology, and the obtained mutants R223P and P242F have higher catalytic activity and can be applied to catalysis of carbon dioxide reduction. The catalyst can catalyze CO2 to generate formic acid more effectively in vitro, and has potential application value in the aspects of efficient activation of CO2 and further conversion of CO2 into other mono-carbon compounds through cascade reaction.

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 belongs to the technical field of enzyme engineering, and particularly relates to a P450 peroxygenase mutant and application of the P450 peroxygenase mutant in degradation of phenol environmental pollutants. The mutant is formed by mutating phenylalanine into alanine from the 46th amino acid of P450 peroxygenase with an amino acid sequence as shown in a sequence table SEQ ID NO.1, and the amino acid sequence of the P450 peroxygenase is as shown in a sequence table SEQ ID NO.2. The P450 peroxygenase mutant provided by the invention has the advantages of high catalytic efficiency, high protein expression quantity, low industrial cost and the like. The operation process for degrading the phenol environmental pollutants is simple, the process is mature, the cost is low, harmful impurities are not contained, and the method is non-toxic and environment-friendly.

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 organic synthesis, and particularly discloses an ammonia aromatic alkene modified near-infrared BODIPY fluorescent probe as well as a preparation method and application thereof.The near-infrared BODIPY fluorescent probe is obtained by adopting 6-(dimethylamino) nicotinic aldehyde to directionally modify the alpha position of BODIPY and constructing an expanded conjugated system through Knoevenagel condensation. Wherein dimethylamino provides a strong electron donating effect, a molecular structure is twisted into a non-planar configuration due to steric hindrance of a pyridine ring, pi-pi accumulation is reduced, and an ACQ effect is inhibited. According to the structural modification strategy, significant red shift of absorption / emission wavelength is realized by expanding a molecular pi-conjugated skeleton, and meanwhile, the stability of the BODIPY core and the quantum yield are effectively enhanced. The probe molecule can specifically recognize the diphenylalanine dipeptide structural unit by utilizing the synergistic coordination effect of the 2-aminopyridine derivative and the BODIPY mother nucleus, so that the selective detection of the Alzheimer's disease biomarker Abeta42 is realized, and a novel optical detection tool is provided for the early molecular diagnosis and targeted therapy of AD (Alzheimer's disease).

The invention discloses a 3 '-phosphoadenosine-5'-phosphoryl sulfate synthetase mutant and an application of the 3 '-phosphoadenosine-5'-phosphoryl sulfate synthetase mutant. Compared with a wild enzyme amino acid sequence as shown in SEQ ID NO.1, the amino acid sequence of the 3 '-adenosine-5'-phosphoryl sulfate synthetase mutant has one or two mutations in the 101 site, the 207 site and the 560 site; preferably, phenylalanine at the 101 site is mutated into tryptophan; cysteine at the 207th site is mutated into glycine; phenylalanine at the 560th site is mutated into tryptophan. The invention also provides a synthesis method and application of the 3 '-adenosine-5'-phosphoryl sulfuric acid. The APS intermediate product inhibition effect of hPAPSS1 is relieved through a point mutation technology, the substrate affinity of hPAPSS1 to ATP is improved, and a mutant enzyme with a high PAPS conversion rate is obtained; and the bifunctional enzyme hPAPSS1 is synthesized by heterologous expression of PAPS in escherichia coli, so that the acquisition of the enzyme is simplified, and the synthesis efficiency of PAPS is improved.

The invention relates to the technical field of bioactive peptides, in particular to a novel multifunctional collagen-like tripeptide and application thereof, an amino acid sequence contains multiple combinations, X can be selected from multiple components, 3-methoxy-4-hydroxyphenylalanine and the like are added, and the novel multifunctional collagen-like tripeptide can interact with specific proteins, activate related pathways and play multiple physiological functions and is applied to multiple fields. The collagen-like tripeptide has obvious advantages, innovates component expansion functions, improves the preparation method, improves the efficiency, reduces the cost, is matched with other components in the fields of beauty, health care and medicine, enhances the efficacy, realizes targeted delivery, and brings a new opportunity to related industries.

The invention relates to the field of biological engineering and technology, in particular to an enzyme for synthesizing glabridin, a biological synthesis method of glabridin and a bacterial strain. The invention discloses a series of glabridin synthesizing enzymes (phenylalanine ammonialyase, cinnamic acid-4-hydrogenase, tyrosine ammonialyase, p-coumaric acid coenzyme A ligase, chalcone synthase, chalcone reductase, chalcone isomerase, isoflavone synthase, 2-hydroxyisoflavone dehydratase, 4 '-oxymethyltransferase, 4'-hydroxymethyltransferase and 4 '-hydroxymethyltransferase) derived from glycyrrhiza glabra for the first time. ) can be used in the preparation of a compound (e.g., isoflavone 2 '-hydrogenase, isoflavone reductase, Vissisoketoreductase, isoprenyltransferase, pterocarpin reductase, oxidative cyclase, demethylase, cytochrome P450 reductase, and the like). The de novo synthesis of the glabridin in a microbial cell factory is realized for the first time, and the application prospect of the glabridin biological manufacturing industry is greatly promoted.

The present invention belongs to the technical field of biological prevention and treatment for viral diseases. Disclosed in the present invention are a tomato disease-resistant gene mutant, and the use thereof in the prevention and treatment of ToBRFV. It is found in the present invention that mutating the nucleotide at position 1927 of the coding region sequence of tomato Tm-22 gene from G to A, or mutating the amino acid at position 643 of the LRR domain of a protein that is encoded by tomato Tm-22 gene from glycine to arginine can remarkably reduce the accumulation level of ToBRFV capsid protein (CP). The gene (named Tm-22-Mut5) can serve as a novel ToBRFV resistant gene, and also retains the resistance to TMV, ToMV and ToMMV. The Tm-22-Mut5 and a pre-screened Tm-22-Mut3-1 mutant (tyrosine at position 767 of the LRR domain thereof is mutated to phenylalanine) undergo combinatorial mutagenesis to obtain a mutant Tm-22-Mut6. Analysis shows that the Tm-22-Mut6 can remarkably reduce the accumulation level of the ToBRFV capsid protein. Compared with the pFGCTm-22-Mut3-1 mutant obtained by screening in the previous research and the newly obtained mutant Tm-22-Mut5, the Tm-22-Mut6 has further improved resistance to ToBRFV.

The invention discloses a p-nitrophenyl ethyl esterase mutant with high enantioselectivity as well as a construction method and application of the p-nitrophenyl ethyl esterase mutant. The p-nitrophenyl ethyl esterase mutant is obtained by mutating an amino acid sequence of wild p-nitrophenyl ethyl esterase pnbA as shown in SEQ ID NO.1 according to one or a combination of more of the following modes: leucine at the 273rd site is mutated into aspartic acid, phenylalanine at the 314th site is mutated into histidine, and leucine at the 362nd site is mutated into arginine. The mutant pnbA-L273D / F314H / L362R provided by the invention shows optimal catalytic performance (E = 47.16) for racemization-acetic acid pinyl hydrate, the enantiomeric excess value of the mutant is 95.13%, the conversion rate of 1S, 5R-acetic acid pinyl hydrate is 90.42%, the enantioselectivity of the mutant is obviously higher than that of a wild type, and the mutant has great application potential in biological catalytic synthesis of monocyclic monoterpenoid chiral alcohols.

The invention discloses a pichia pastoris engineering bacterium for synthesizing bakuchiol from de novo by converting methanol as well as construction and application of the pichia pastoris engineering bacterium. A heterologous p-coumaric acid synthesis pathway is introduced to neutral sites of different chromosomes of pichia pastoris, a high-yield p-coumaric acid strain is obtained through gene knockout, overexpression or heterologous expression of tyrosine and phenylalanine synthesis pathway key genes of a shikimic acid pathway, a heterologous bakuchiol biosynthesis pathway is introduced on the basis, and a high-yield p-coumaric acid strain is obtained. After overexpression of bakuchiol synthetase, endogenous overexpression or heterologous expression of MVA pathway key genes and exogenous acetyl coenzyme A supply pathway genes, methanol concentration optimization and bacterial strain His4 gene supplementation, the yield of bakuchiol is effectively increased to 91.2 mg / L and is increased by 59.8 times compared with that of an initial bacterial strain, and the yield of bakuchiol in a 15L fermentation tank reaches 692.8 mg / L. The method has the characteristics of high conversion efficiency, low production cost, convenience in preparation, wide industrial application prospect and the like.

The invention belongs to the technical field of bioengineering, and relates to a transaminase mutant, a recombinant genetically engineered bacterium and application of the transaminase mutant in catalytic synthesis of (R)-1-Boc-3-aminopiperidine.The transaminase mutant is obtained by conducting single-point or combined mutation on the 131 site and / or the 197 site of an amino acid sequence shown in SEQ ID NO.2; the mutation sites comprise that the 131 phenylalanine is mutated into aspartic acid, threonine or tyrosine, and / or the 197 lysine is mutated into arginine or leucine. Experimental results show that compared with wild type transaminase, the catalytic activity, the thermal stability and the organic solvent tolerance of the obtained mutants, especially single-point mutants MyTA1-F131Y and MyTA1-K197R and a combined mutant MyTA1-F131Y-K197R, are all remarkably improved, and compared with the wild type transaminase, the catalytic activity, the thermal stability and the organic solvent tolerance of the obtained mutants are all remarkably improved. The mutant MyTA1-F131Y-K197R can be used for efficiently catalyzing asymmetric amination of N-Boc-3-piperidone to synthesize (R)-1-Boc-3-aminopiperidine, the conversion rate of the (R)-1-Boc-3-aminopiperidine after the (R)-1-Boc-3-aminopiperidine reacts for 24 hours under the condition that the substrate concentration is 100 g / L can reach 90% or above, and the mutant MyTA1-F131Y-K197R has a good industrial application prospect.

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 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 is applicable to the technical field of biomedicine, and provides dipeptide-photosensitizer molecule co-assembled nanoparticles as well as a preparation method and application thereof. According to the invention, cationic diphenylalanine (CDP) and a biological cross-linking agent genipin are self-assembled to form a dipeptide carrier, and then the dipeptide carrier and a photosensitizer molecule chlorin e6 (Ce6) are co-assembled, so that nanoparticles with controllable size, controllable drug loading capacity and good biocompatibility are successfully prepared. The preparation method is simple and easy to implement, effectively solves the key problems that the traditional photosensitizer molecule Ce6 is poor in biocompatibility and easy to gather, not only can efficiently deliver Ce6, but also obviously improves the application safety and biocompatibility of Ce6. The Ce6 is almost free of dark toxicity under a dark condition, can play a strong photodynamic killing role under illumination, and greatly improves the possibility and application potential of the Ce6 in tumor photodynamic therapy by virtue of the flexible regulation and control advantages of the size and the drug loading capacity.

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.

The application discloses a formic acid dehydrogenase mutant and application thereof in catalyzing carbon dioxide reduction. Paracoccus The formic acid dehydrogenase from sp.MKU1 is mutated by a site-directed mutation technology Ps The arginine (Arg) at the 223th position of the FDH48 amino acid sequence is mutated into proline (Pro) or the proline (Pro) at the 242th position is mutated into phenylalanine (Phe), and the obtained mutants R223P and P242F have higher catalytic activity, can more effectively catalyze CO2 to generate formic acid in vitro, and have potential application values in efficient activation of CO2 and further conversion into other one-carbon compounds through cascade reactions.

The invention discloses a tomato disease-resistant gene mutant and application thereof in prevention and treatment of ToBRFV, and belongs to the technical field of biological prevention and treatment of viral diseases. According to the invention, the 1927th nucleotide of the coding region sequence of the tomato Tm-22 gene is mutated from G to A; or the 643th amino acid of the LRR structural domain of the tomato Tm-22 gene encoding protein is mutated from glycine to arginine, so that the accumulation level of ToBRFV capsid protein (CP) can be obviously reduced. The gene (named as Tm-22-Mut5) not only can be used as a new ToBRFV resistance gene, but also retains the resistance to TMV, ToMV and ToMMV. The method comprises the following steps: carrying out combined mutation on Tm-22-Mut5 and a Tm-22-Mut3-1 mutant (tyrosine at the 767th site in an LRR structural domain is mutated into phenylalanine) screened in an earlier stage, so as to obtain a mutant Tm-22-Mut6. According to the present invention, the analysis results show that the accumulation level of the ToBRFV capsid protein can be significantly reduced by using the Tm-22-Mut6; compared with a mutant pFGCTm-22-Mut3-1 obtained through early research and screening and a newly obtained mutant Tm-22-Mut5, the resistance of the Tm-22-Mut6 to the ToBRFV is further improved, and the resistance of the Tm-22-Mut6 to the ToBRFV is further improved.

The application discloses a kind of nano magnetic flocculants and its preparation method and application, belong to drinking water processing technical field, including the following steps: step S1, modified ferroferric oxide nanosphere is ultrasonically dispersed in ammonia alcohol solution, while stirring, slowly drop adding tetraethyl orthosilicate, continue stirring after drop, after centrifugal separation, wash, obtain silica coated ferroferric oxide nanoparticles;Step S2, phenylalanine modified chitosan is added into glacial acetic acid solution, after completely swelling and dissolving, add silica coated ferroferric oxide nanoparticles and ultrasonic treatment, under low pressure ultraviolet lamp, then with anhydrous ethanol wash purification, vacuum drying to constant weight, obtain nano magnetic flocculants;The method of the application is simple and easy to operate, the nano magnetic flocculants prepared can be quickly adsorbed to the surface of sulfonamide antibiotics, produce flocculation and can be magnetically separated, very suitable for trace sulfonamide antibiotics in drinking water source efficient removal.

The invention discloses a T7-RNA polymerase mutant and application thereof, and relates to the field of nucleic acid tool enzymes and nucleic acid biology. The T7-RNA polymerase mutant is obtained by mutating glycine at the 47th site from the N end of a full-length amino acid sequence of wild type T7-RNA polymerase into phenylalanine, tryptophan or tyrosine; or, the amino acid sequence of the T7-RNA polymerase mutant and the amino acid sequence of the wild type T7-RNA polymerase have at least 80% homology, and glycine in a peptide fragment as shown in SEQ ID NO.10 in the amino acid sequence is mutated into phenylalanine, tryptophan or tyrosine; the full-length amino acid sequence of the wild type T7-RNA polymerase is as shown in SEQ ID NO. 1. The T7-RNA polymerase mutant is suitable for enzymatic synthesis of RNA, and has strong application potential in the aspects of in-vitro transcription, RNA synthesis, RNA drug synthesis, RNA vaccine manufacturing, gene editing, in-vivo protein expression or in-vitro translation systems and the like.

The invention discloses a construction method of a cyanobacteria-corynebacterium glutamicum artificial photosynthetic mixed bacteria system. The construction method comprises the following steps: step S1, amplifying by taking plasmid pUC-tho as a template to obtain a theophylline inducible promoter Ptho; step S2, carrying out amplification by taking a Synechocystis sp. PCC 6803 genome as a template so as to obtain a strong promoter Pcpc560, and carrying out amplification on the strong promoter Pcpc560 so as to obtain a strong promoter Pcpc560; step S3, carrying out amplification by taking the plasmid pUC-PAL as a template to obtain an arabidopsis thaliana phenylalanine lyase gene pal; step S4, carrying out amplification by taking the plasmid pUC-cscB as a template to obtain an escherichia coli W sucrose transporter gene cscB; step S5, carrying out amplification by taking the integrated plasmid Pcp3031 as a template, so as to obtain a terminator Trbcl; and step S6, fusing the strong promoter Pcpc560, the arabidopsis phenylalanine lyase gene pal and the terminator Trbcl, and respectively connecting with an expression vector pSI-SPE to obtain the expression vector containing the gene pal. According to the invention, a'cyanobacteria-corynebacterium glutamicum 'artificial photosynthetic mixed bacteria system is constructed by simulating a mutualistic symbiotic relationship ubiquitous in nature, and negative carbon biosynthesis of cis-muconic acid is realized.

In the first aspect, the present disclosure provides a Lactoferrin polypeptide fragment, where the Lactoferrin polypeptide fragment has an amino acid sequence shown in SEQ ID NO: 1. In the second aspect, the present disclosure provides a preparation method of the Lactoferrin polypeptide fragment, including: protecting amino acids using a 9-fluorenylmethoxycarbonyl (Fmoc) protecting group, coupling the amino acids with a P-hydroxymethylphenoxymethyl polyethylene resin (HMP resin) in an order of cysteine, alanine, leucine, cysteine, glutamate, threonine, asparagine, aspartate, asparagine, phenylalanine, leucine, leucine, asparagine, and lysine, and separating the HMP resin to obtain a target Lactoferrin polypeptide fragment. In the third aspect, the present disclosure further provides an anti-Lactoferrin antibody prepared using the Lactoferrin polypeptide fragment, and use of the Lactoferrin polypeptide fragment in preparation of an anti-Lactoferrin flow cytometric antibody and in preparation of a Lactoferrin detection product.

The invention discloses an amino acid composition for treating alopecia and application of the amino acid composition in preparation of a medicine for treating alopecia, and belongs to the field of medicine configuration products, the amino acid composition is composed of a targeting core intervention component and an auxiliary strengthening synergistic component, the targeting core intervention component is prepared from 30-50 parts of arginine, 50-155 parts of lysine and 50-120 parts of glutamic acid, and the auxiliary strengthening synergistic component is prepared from an auxiliary strengthening synergistic component and an auxiliary strengthening synergistic component. 10 to 40 parts of cysteine and 20 to 60 parts of leucine; the auxiliary strengthening synergistic component is prepared from 15 to 45 parts of tyrosine, 15 to 40 parts of glycine, 10 to 40 parts of glutamine, 20 to 35 parts of serine, 5 to 25 parts of alanine, 2 to 20 parts of aspartic acid and 15 to 35 parts of phenylalanine; the composition can be used as an active ingredient to be prepared into different dosage forms such as a pigmentum, a spray, an ointment and a liniment, is applied to prevention of alopecia and promotion of hair growth, and has a remarkable treatment effect.

According to the scheme, the invention provides the recombinant macrolide enzyme as well as the preparation method and the application thereof, the amino acid sequence of the recombinant macrolide enzyme is as shown in SEQ ID NO.1, and the recombinant macrolide enzyme is derived from an EreC esterase family of enterobacter hormaechei and is obtained through site-specific mutagenesis; the mutation sites are as follows: glutamic acid at the 44th site is mutated into asparagine, tyrosine at the 55th site is mutated into proline, proline at the 76th site is mutated into arginine, phenylalanine at the 153rd site is mutated into alanine, and serine at the 219th site is mutated into glutamic acid. The method is expected to remove macrolide antibiotic pollution, and has good economic benefits and practical values.

A Levodopa-selective sensor is provided. A continuous levodopa monitor is also provided. The levodopa sensor includes a sensor area having a working electrode with a levodopa-selective chemistry configured for at least partial implantation in a host. The sensor also includes at least one membrane adjacent the levodopa-selective chemistry. The at least one membrane includes an enzyme domain that at least one enzyme selected from a tyrosinase; a mutated tyrosinase with specificity towards I-3,4-dihydroxyphenylalanine; a dihydroxyphenylalanine 4,5-dioxygenase; a mutated dihydroxyphenylalanine 4,5-dioxygenase with specificity towards I-3,4-dihydroxyphenylalanine; and combinations thereof; a synthase enzyme with specificity towards I-3,4-dihydroxyphenylalanine; a mutated synthase enzyme with specificity towards I-3,4-dihydroxyphenylalanine; a 3,4-dihydroxyphenyl-acetaldehyde synthase; a mutated 3,4- dihydroxyphenyl-acetaldehyde synthase with specificity towards I-3,4-dihydroxyphenylalanine; a dioxygenase enzyme with specificity towards I-3,4-dihydroxyphenylalanine; and a mutated dioxygenase enzyme with specificity towards I-3,4-dihydroxyphenylalanine.

The invention discloses application of copper-amino acid nano enzyme in preparation of anti-inflammatory drugs, and relates to the technical field of biomedical new materials, amino acids comprise glycine, arginine, histidine, threonine, phenylalanine and cysteine; the ratio of the amino acid to the copper ions is 1: (0.5-5), and the synthesis temperature of the copper-cysteine nano enzyme is 25-125 DEG C. The copper-amino acid nano-enzyme library established by the invention has efficient hydroxyl free radical, superoxide free radical and hydrogen peroxide scavenging activity; wherein the copper-cysteine nano-enzyme shows the highest enzymatic activity, and shows low toxicity and good biocompatibility in both the cell level and the animal level; meanwhile, the copper-cysteine nano-enzyme also shows anti-inflammatory activity and anti-oxidative stress activity, can remarkably improve cell inflammation and body inflammation, relieves and treats dextran sodium sulfate induced mouse ulcerative colitis, and can be further applied to preparation of drugs for treating inflammatory bowel diseases.

The invention relates to the technical field of biological catalysis, and discloses an M88F mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: M88F: methionine of the 88th amino acid sequence of UGT76G1 is mutated into phenylalanine; and the substrate rebaudioside A (RA) can be efficiently and directionally converted into rebaudioside I (RI) with higher value. In an optimized reaction system, the conversion rate stably reaches 40%, and the catalytic efficiency is improved by more than 5-8 times compared with the common reference enzyme. The enzyme preparation has the characteristics of high catalytic activity, mild reaction conditions, simplicity and convenience in operation and the like, shows good stability and reproducibility in laboratory research and large-scale production, and has a wide industrial application prospect.

Disclosed herein are inhibitors of 4-hydroxyphenylpyruvate dioxygenase (HPD or HPPD) that have decreased inhibitory activity against sepiapterin reductase (SPR). Disclosed herein are methods of administering an HPD inhibitor alone or in combination with a diet low in tyrosine and / or phenylalanine, with or without dihydrobiopterin (BH2) and / or tetrahydrobiopterin (BH4) supplementation and / or monoamine salvage therapy. The compounds of the present disclosure can be used to treat conditions responsive to modulation or inhibition of HPD, such as inborn errors of metabolism, including tyrosinemia. The compounds of the present disclosure can also be used as herbicides to control weeds.

The invention discloses an engineered glycosyl transferase and application thereof in efficient preparation of triterpenoid saponin. The engineered glycosyl transferase is obtained by mutating serine at the 15th site of UGT74AC1 enzyme into alanine, mutating histidine at the 47th site into aspartic acid, mutating leucine at the 48th site into valine, mutating alanine at the 180th site into serine, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid The mutant is obtained by mutating serine at the 332 site into proline, phenylalanine at the 367 site into tryptophan and lysine at the 420 site into arginine. According to the invention, the glycosyl transferase with high catalytic activity is obtained by modifying an enzyme engineering technology, and good application of the glycosyl transferase in synthesis of triterpenoid saponin is realized. The glycosyl transferase disclosed by the invention can also be coupled with sucrose synthase, or coupled with N-acetylhexosamine kinase and N-acetylglucosamine-1-uridine phosphate transferase, and acetylglucosamine is used as a glycosyl donor, so that cascade production of triterpenoid saponin with lower cost and higher efficiency is realized.

The invention discloses a multifunctional cyclic peptide, and the structure of the multifunctional cyclic peptide is an end-to-end cyclization structure of tryptophan, leucine, lysine, arginine, tryptophan, leucine, arginine, lysine, leucine, tyrosine, lysine, phenylalanine, glycine and glycine. The multifunctional cyclic peptide has the advantages of the cyclic peptide, can be used as a novel bioactive molecule integrating antibacterial, anti-inflammatory and osteogenesis / tooth promoting functions, can meet various clinical requirements, and has a wide application prospect.