49 results about "Nitrilase" patented technology

The present invention relates to a process for the preparation of substituted 4-(N′-hydroxy-carbamimidoyl)benzoic acids, which can be obtained by nitrilase catalyzed hydration of substituted terephthalonitriles of formula (II) in an aqueous medium to afford (ammonium) 4-cyanobenzoic acids (IIa). The hydration is followed by treatment of the aqueous reaction medium with hydroxylamine or a salt thereof to afford amidoximes (I).

This invention provides a nitrile hydrolase mutant and its application in the synthesis of p-cyanobenzoic acid. The invention provides a nitrile hydrolase mutant that enhances the catalytic activity for the synthesis of p-cyanobenzoic acid. The mutant protein is a non-natural protein, and it exhibits significantly enhanced activity in catalyzing the conversion of terephthalonitrile to p-cyanobenzoic acid. Furthermore, the mutant protein contains mutations in two or more core amino acids related to the enzyme's catalytic activity in the wild-type nitrile hydrolase. The nitrile hydrolase mutant of this invention can significantly improve the yield of the synthesized product catalyzed by the nitrile hydrolase.

The invention discloses an ancestor nitrilase design based on multi-sequence alignment and machine learning and application of a mutant, and belongs to the technical field of enzyme engineering. The invention designs an ancestor enzyme sequence-structure-molecular dynamics strategy so as to obtain information for eradicating ancestor enzyme in an evolutionary landscape, specifically, a nitrilase sequence is collected for evolutionary tree analysis to obtain the evolutionary landscape, an ancestor enzyme reconstruction algorithm is combined to obtain an amino acid sequence of the ancestor enzyme, and an ancestor enzyme primary structure sequence library is constructed; predicting the tertiary structures of all ancestor enzymes to obtain a structural library; and finally, carrying out molecular dynamics simulation on all ancestor enzyme tertiary structures to obtain a kinetic parameter library, and screening through specific kinetic parameters. Based on the strategy, ancestor nitrilase capable of tolerating 90 DEG C is obtained, the thermal stability of the ancestor nitrilase is evolved, and a series of dominant mutants are obtained.

The invention discloses a nicotinic acid immobilized enzyme conversion method, which comprises the following steps: taking wet thalli containing nitrilase, preparing a flocculation clear liquid, passing the flocculation clear liquid through an ultrafiltration membrane, carrying out embedding immobilization to obtain embedded particles not greater than 2mM, and after the embedded particles are hardened, separating and purifying the obtained conversion liquid by adopting a membrane separation method to obtain the nicotinic acid immobilized enzyme. Sequentially carrying out microfiltration, activated carbon decoloration, ultrafiltration, nanofiltration decoloration, acidification crystallization and centrifugation to finally obtain a nicotinic acid finished product. The immobilized enzyme prepared by the method disclosed by the invention can stably exist in nitrile substances, can be repeatedly used for many times, and is high in stability and low in enzyme activity loss rate, and a separated and purified product is free of impurities and high in yield.

The invention discloses a nitrilase mutant and an application of the nitrilase mutant in synthesis of chiral cyanamide. Compared with an amino acid sequence of wild nitrilase amine, the nitrilase mutant protein has the advantages that the nitrilase mutant protein has a higher amino acid sequence; mutation exists at any one or more of the following amino acid sites corresponding to the amino acid sequence as shown in SEQ ID NO.1: the 54th site, the 118th site, the 120th site, the 139th site, the 148th site, the 168th site, the 170th site, the 194th site, the 197th site, the 198th site, the 202 site and / or the 225th site. The mutant constructed by the method disclosed by the invention can be used for efficiently catalyzing a 3-substituted-glutaronitrile compound to generate an (S)-3-substituted-4-cyanobutyramide compound. According to the invention, the problem of insufficient catalytic activity of the existing enzyme is solved, and an efficient scheme is provided for green synthesis of chiral cyanamide.

This invention belongs to the field of enzyme engineering technology, specifically relating to an enzyme engineering method and its application in biocatalysis. Based on the excellent performance optimization capabilities of the deep learning-guided protein sequence design model ProteinMPNN, this invention developed a computational design framework called DeepPCD. This framework integrates deep learning-guided sequence design, physical energy calculation, and molecular dynamics simulation, constructing a three-level intelligent screening process from "massive generation" to "high-precision prediction." Using this strategy, nitrile hydrolase (EC 3.5.5.1) was mutated, resulting in a nitrile hydrolase mutant with improved stability, specificity, and enzyme activity, capable of efficiently and specifically catalyzing the hydrolysis of nitrile compounds to carboxylic acids.

The invention discloses a nitrilase mutant and an application of the nitrilase mutant in preparation of (S)-3-methylheptanoic acid. The nitrilase mutant disclosed by the invention has high catalytic activity and stereoselectivity, and can overcome the defects of low substrate concentration, low stereoselectivity, high cost, environmental pollution and the like in the existing method, so that 3-methylheptonitrile can be quickly catalyzed to generate (S)-3-methylheptanoic acid under high substrate concentration. In addition, the method also has the effects of good enzyme catalysis effect, high product purity, high recovery rate, simple steps, greenness, environmental protection and the like.

The invention discloses a directed evolution method for improving thermal stability of nitrilase, and belongs to the technical field of enzyme engineering. The ancestor enzyme with improved thermal stability is obtained by the following method: collecting a sequence of nitrilase, carrying out evolutionary tree analysis to obtain an evolutionary landscape, obtaining an amino acid sequence of the ancestor enzyme in combination with an ancestor enzyme reconstruction algorithm, and constructing an ancestor enzyme primary structure sequence library; predicting the tertiary structures of all ancestor enzymes to obtain a structural library; and finally, carrying out molecular dynamics simulation on all the ancestor enzyme tertiary structures to obtain a kinetic parameter library, and screening through specific kinetic parameters to obtain the novel heat-resistant ancestor nitrilase. And then predicting and verifying mutation sites, and screening out a forward mutant with improved thermal stability and enzyme activity.

The invention discloses a nitrilase mutant and an application technology thereof in synthesis of nicotinic acid, and belongs to the technical fields of gene engineering, enzyme engineering and biological catalysis. The nitrilase mutant disclosed by the invention is obtained by mutating nitrilase from a source of Pseudomonas putida CGMCC (China General Microbiological Culture Collection Center) 3830, and the heterologous expression of the nitrilase mutant in corynebacterium glutamicum is successfully realized. The optimal mutant can efficiently catalyze a substrate 3-cyanopyridine to synthesize 550.68 g / L of nicotinic acid, and the conversion rate is 91.37%.

The invention discloses a nitrilase mutant and application thereof in synthesis of a gamma-aminobutyric acid derivative, the nitrilase mutant with improved catalytic activity and stereoselectivity is constructed to efficiently catalyze hydrolysis of 2-substituted succinonitrile to synthesize 3-substituted-3-cyanopropionic acid, and the gamma-aminobutyric acid derivative is further synthesized through hydrogenation. And a foundation is laid for industrial production of gamma-aminobutyric acid drugs synthesized by a nitrilase method.

The invention discloses a nitrilase mutant with high activity and stereoselectivity and application of the nitrilase mutant in synthesis of chiral carboxylic acid. The mutant is obtained by performing single mutation or multiple mutation on 79th, 166th, 167th and 246th amino acids of an amino acid sequence shown as SEQ ID NO.1. The invention further discloses a preparation method of the nitrilase mutant. According to the invention, the nitrilase OsNIT-mut is subjected to molecular modification through (semi) rational design, and a mutant with synergistically improved hydrolysis reaction specificity and stereoselectivity is obtained. The content of mandelic acid in a product of the mutant OsNIT-mut / V246N / T166G / R79Y / A167N for catalyzing mandelonitrile is 90.5%, the e.e. Value of R-mandelic acid is increased to 95.2%, and the relative hydrolytic activity is 399.1%. The nitrilase mutant can be applied to green industrial catalytic synthesis of chiral mandelic acid through regulation and control of hydrolysis reaction specificity and stereoselectivity, and has important significance.

The invention discloses construction and application of a novel nitrilase with excellent amide generation capability and a mutant thereof. The amino acid sequence of the nitrilase disclosed by the invention is as shown in SEQ ID NO: 1, and a mutant of the nitrilase is obtained by performing single mutation on the 166th site, the 168th site and the 191th site of the sequence as shown in SEQ ID NO: 1. The nitrilase provided by the invention has excellent amide generation capability, and has important industrial application potential for green and efficient preparation of amide compounds.

The invention relates to the technical field of organic synthesis, in particular to a biological catalysis method for synthesizing 4-acetyl-2-methyl benzoic acid based on 4-acetyl-2-methyl cyanophenyl. Free or immobilized nitrilase is mostly adopted in a biological catalysis method, and the conversion rate of 4-acetyl-2-methylbenzonitrile is poor. In order to solve the technical problems, the invention provides the biological catalysis method for synthesizing the 4-acetyl-2-methyl benzoic acid based on the 4-acetyl-2-methyl cyanophenyl, and the method comprises the following steps: by taking the 4-acetyl-2-methyl cyanophenyl as a reaction substrate, resting cells of Rhodococcus sp. CCZU10-1 as a catalyst and a deep eutectic solvent (DES) as a cosolvent, synthesizing the 4-acetyl-2-methyl benzoic acid on the basis of the 4-acetyl-2-methyl cyanophenyl. A phosphoric acid buffer solution is used as a reaction solvent, 4-acetyl-2-methyl benzoic acid is obtained through catalytic stirring hydrolysis reaction, the reaction condition is mild, DES is green and low in toxicity and biodegradable, the substrate conversion rate is high (gt, 95%), the product selectivity is good, the process environment is friendly, and the green chemical principle is met.

The invention belongs to the field of enzyme engineering and agricultural waste conversion, and particularly relates to an acid-resistant and heat-resistant nitrilase mutant and application thereof in fermentation of rapeseed meal. Aiming at the conditions that the existing nitrilase is insufficient in acid resistance and heat resistance and relatively low in activity, the nitrilase RsNit anchored on the surface capsid protein cotG of bacillus subtilis DB403 is used as a starting target for modification; according to the nitrilase mutant disclosed by the invention, a catalytic hot spot existing in an active center is found by carrying out semi-rational design on amino acid at the active center, and combined mutation is carried out on the catalytic hot spot, so that it is found for the first time that RsNit has a catalytic hot spot on 4-pentenenitrile at the active center, and a nitrilase mutant of which the activity, the thermal stability and the acid tolerance are all remarkably improved is successfully screened out; the method is applied to fermentation of the rapeseed meal, so that full utilization of the rapeseed meal in livestock and poultry feed is promoted, and the method has a wide market application prospect.

The application discloses a nitrilase mutant and application thereof in synthesis of chiral cyanoamide, wherein the nitrilase mutant has mutations in any or any of the following amino acid positions corresponding to the amino acid sequence shown in SEQ ID NO. 1: 54th, 118th, 120th, 139th, 148th, 168th, 170th, 194th, 197th, 198th, 202th and / or 225th, compared with the amino acid sequence of wild-type nitrilase amine. The mutant constructed by the application can efficiently catalyze 3-substituted-glutaronitrile compounds to generate (S)-3-substituted-4-cyanobutyramide compounds. The application solves the problem of insufficient enzyme catalytic activity in the prior art, and provides an efficient scheme for green synthesis of chiral cyanoamide.

The present application provides a nitrilase mutant and its application. Compared with a wild-type nitrilase with an amino acid sequence shown in SEQ ID NO: 2, the nitrilase mutant comprises one or more of the following amino acid mutation sites: S201F, G239M, K242T, V243Q and G246Q. The present application constructs a nitrilase mutant with high enzyme activity, high salt tolerance and high substrate tolerance by mutating and modifying a nitrilase derived from Alcaligenes.

The invention belongs to the technical field of enzyme engineering and biology, and discloses a nitrilase mutant as well as a coding gene, a recombinant vector, a recombinant gene engineering bacterium, an enzyme preparation and application thereof. The nitrilase mutant is obtained by carrying out single-point mutation or multi-point mutation on 8th, 17th, 35th or 150th amino acids of an amino acid sequence of the nitrilase as shown in SEQ ID NO.2. The invention further discloses a preparation method of the nitrilase mutant. Compared with wild type Gi-Nit, the nitrilase mutant disclosed by the invention has the advantages that the activity is improved by 32 times, the yield is improved by 15.8 times, and a foundation is laid for synthesizing 2-(4-nitrophenyl) butyric acid by an industrial enzyme method.

The application discloses application of a nitrilase in selective catalysis of 6-chloronicotinonitrile to synthesize 6-chloronicotinic acid and a mutant, wherein the nitrilase mutant is obtained by mutating alanine at the 55th position of the amino acid shown in SEQ ID NO. 2 into serine. In an optimal system, the hydrolysis activity of the nitrilase to 6-chloronicotinonitrile reaches 450 U / g (WCW), 300 g / L 6-chloronicotinonitrile can be catalyzed to synthesize 6-chloronicotinic acid, the yield reaches 92%, and the catalysis synthesizes 2-chloronicotinamide with a concentration of up to 4.8 g / L; when the nitrilase mutant is used to catalyze 6-chloronicotinonitrile, the activity reaches 580 U / g (WCW), 300 g / L 6-chloronicotinonitrile can be catalyzed to synthesize 6-chloronicotinic acid, the yield reaches 99%, and the hydration activity of 2-chloronicotinonitrile is eliminated, and 2-chloronicotinamide is not generated.

The present invention provides a nitrilase mutant and application thereof in the synthesis of 1-cyanocyclohexyl acetic acid, the nitrilase mutant is obtained by mutating one or two of the amino acids at position 180 and 205 of the amino acid sequence shown in SEQ ID No. 2. In the present invention, by semi-rational design and protein molecular modification, the specific enzyme activity of the nitrilase double mutant AcN-G180D / A205C was increased by up to 1.6 folds, and the conversion rate>99%. And the reaction time was shortened to a quarter of the original using the recombinant Escherichia coli containing the nitrilase mutant to hydrolyze 1-cyanocyclohexylacetonitrile at high temperature (50° C.). Therefore, the mutants obtained by the present invention have a good application prospect in efficiently catalyzing 1-cyanocyclohexylacetonitrile to synthesize gabapentin intermediate, 1-cyanocyclohexyl acetic acid.

The present invention belongs to the field of detection technology and relates to a method for detecting organic cyanides by using an inverse opal thin film, which comprises the following steps: Step 1, put the inverse opal thin film into an alkaline solution, observe the photonic crystal reflection peak and its color after equilibrium and stability are achieved, and obtain an inverse opal photonic crystal system; Step 2, oscillate and mix the organic cyanide solution and the nitrile hydratase solution to obtain a mixed solution; put the mixed solution into the inverse opal photonic crystal system, and realize the detection of organic cyanides by observing the color change of the inverse opal photonic crystal system and the movement of the photonic crystal reflection peak. The method for realizing the visual detection of organic cyanides by combining the inverse opal thin film with the enzymatic catalytic reaction breaks through the barriers of poor portability, complex operation and inability to perform on-site analysis of traditional detection technologies. This method is easy to operate, highly portable, highly sensitive, capable of naked-eye observation, and the lowest detection limit can reach 2×10<supgt;‑8< / supgt; g / L.

The invention relates to a novel process for generating N-acetylgalactosamine (GalNAc) clusters using a nitrilase and conjugating said GalNAc clusters to oligonucleotides, such as oligonucleotides for use in therapy. In particular, the nitrilase is used to catalyse the conversion of a trinitrile intermediate to a triacid intermediate.

The application discloses a nitrilase mutant PgNIT2-A190I, which is obtained by point mutation of alanine at the 190th position of nitrilase PgNIT2 of Paraburkholderia graminis C4D1M into isoleucine. Accordingly, the inventors also design a recombinant plasmid of a nitrilase mutant PgNIT2-A190I coding gene, and construct a corresponding recombinant genetically engineered bacterium. Researches show that, with 3-butenenitrile and 4-pentenenitrile as substrates, the enzyme activity of the nitrilase and the mutant PgNIT2-A190I of the application is 5.94 U / mg and 6.66 U / mg, 9.95 U / mg and 11.90 U / mg at pH 7.0 and 45 DEG C respectively, and the nitrilase mutant of the application is significantly improved. Under various substrate concentration conditions, the hydrolysis capacity of the mutant PgNIT2-A190I of the application to 3-butenenitrile and 4-pentenenitrile is also higher than that of the nitrilase PgNIT2. Moreover, the mutant xylanase has good pH and temperature tolerance, and has production application potential in efficient hydrolysis of rapeseed meal glucosinolate derived nitrile compounds.

The invention belongs to the technical field of synthetic biology and metabolic engineering, and particularly relates to a foreign protein expression system with low-degree interference on normal metabolism of a host as well as construction and application of the foreign protein expression system. The system is based on an orthogonal ribosome-mRNA pairing mechanism, an orthogonal SD sequence with complementarity lower than 20% with a host natural anti-SD sequence is obtained through design and screening, a candidate sequence with the host growth inhibition rate lower than 5% is screened from the orthogonal SD sequence, and the optimal orthogonal SD sequence and an orthogonal ASD sequence completely complementary with the optimal orthogonal SD sequence are determined. The system is suitable for high-efficiency expression of esterase, nitrilase and NADPH dependent oxidoreductase, and the enzyme activities of whole cells are respectively improved by 2.5 times, 3.4 times and 2.8 times, so that the system can effectively solve the problems of translation resource competition, high metabolic load, strong protein toxicity, inclusion body formation and the like in the foreign protein expression process; and a universal and stable technical platform is provided for efficient soluble expression of industrial enzymes.

The invention relates to a nitrilase combined mutant and application thereof in whole-cell biological catalysis, and belongs to the technical field of biological catalysis. Through semi-rational design, a double-combination mutant is constructed based on a loop engineering strategy, and the catalytic activity of nitrilase on methylaminoacetonitrile can be remarkably enhanced. The enzyme activity of the nitrilase combined mutant to methylaminoacetonitrile can reach 6.69 U.mL <-1 > and is increased by 8.5 times compared with that of an initial strain. Whole-cell catalysis conditions are further optimized, the nitrilase combined mutant has the highest activity under the conditions that the temperature is 30 DEG C and the pH is 7.2 through a PBS buffer solution, and 75 mM methylaminoacetonitrile can be efficiently converted at the cell concentration of 7.5 g.L <-1 >. The invention provides a novel enzyme tool and process support for efficient biological catalysis of methylaminoacetonitrile.

A method for synthesizing a brivaracetam chiral intermediate (R)-3-cyanohexanoic acid by catalyzing the hydrolysis of 3-cyanohexanitile using an enzyme with nitile hydrolysis activity, and the enzyme with nitrile hydrolysis activity is obtained by carrying out a single mutation or a double mutation on an amino acid at position 140 or an amino acid at position 175 in an amino acid sequence as set forth in SEQ ID NO.2. Compared with a wild type, the nitrilase mutant has the activity increased by 10 times, an ee value increased to 300 or more from 39, a substrate conversion rate of 45%, and a product ee which can reach 98.5%, and the yield of (R)-3-aminomethyl-hexanoic acid by catalytic hydrogenation synthesis using (R)-3-cyanohexanoic acid reaches 85% or more. This features a short synthesis route, mild reaction conditions, and high atom economy, and can be applied to the industrial synthesis of the brivaracetam intermediate.

The application discloses a nitrilase mutant and application thereof in synthesis of gamma-aminobutyric acid derivatives, and relates to a nitrilase mutant with improved catalytic activity and stereoselectivity, which is used for efficiently catalyzing hydrolysis of 2-substituted succinonitrile to synthesize 3-substituted-3-cyanopropionic acid, and further synthesizing gamma-aminobutyric acid derivatives through hydrogenation, thereby laying a foundation for industrialized production of gamma-aminobutyric acid drugs synthesized by the nitrilase method.

The invention discloses nitrilase and an application of the nitrilase in preparation of R-mandelic acid. The nitrilase is wild type nitrilase or a nitrilase mutant, the amino acid sequence of the wild type nitrilase is as shown in SEQ ID NO: 1, and compared with the amino acid sequence as shown in SEQ ID NO: 1, the nitrilase mutant contains one or more amino acid residue differences in S192G, A197S or S285I. When the nitrilase is used for preparing the R-mandelic acid, the conversion rate is high, the ee value of the R-mandelic acid is high, and the nitrilase is suitable for industrial production.

The invention discloses a high-performance nitrilase mutant and application thereof in biocatalytic synthesis of organic acid, and belongs to the technical field of enzyme engineering. According to the method, an ancestor enzyme sequence-structure-molecular dynamics strategy (ASSMD strategy) is designed to obtain information for eradicating ancestor enzyme in an evolutionary landscape, and the ancestor nitrilase capable of tolerating 90 DEG C is obtained by applying the method to mining of extreme thermophilic ancestor nitrilase. Afterwards, the wild-type enzyme is used as a research object, and an evolutionary event causing the extreme heat resistance of the wild-type enzyme is researched. And finally, in combination with the trend that the thermal stability in an evolutionary event is increased firstly and then reduced, determining a thermal stability beneficial residue site, and carrying out independent or combined verification on the thermal stability beneficial residue site to obtain a high-performance mutant.

The application provides a nitrilase mutant and application thereof in feed. Castor meal is the residue after castor seed oil is pressed, and contains rich protein and cellulose. Because the castor meal contains ricin and other toxic substances, the castor meal can cause great harm to poultry and livestock, and the application of the castor meal in the field of feed and fertilizer is limited. Therefore, the application of nitrilase in degrading ricin in castor meal is provided, and single-point mutation or combined mutation is carried out on the 165th, 190th and 221st sites of nitrilase from Streptomyces lunaelactis. The specific enzyme activity of the optimal nitrilase mutant is 840 times that of wild-type nitrilase, most of the ricin can be hydrolyzed in 24 hours, the challenge of adding castor meal as feed is solved, and the nitrilase mutant has great industrial application value.

The invention belongs to the technical field of enzyme engineering and biology, and discloses a nitrilase mutant as well as a coding gene, a recombinant vector, a recombinant gene engineering bacterium, an enzyme preparation and application thereof. The nitrilase mutant is obtained by performing single-point mutation or multi-point mutation on the 16th, 23rd or 47th amino acid of the amino acid sequence of the nitrilase as shown in SEQ ID NO.2. The invention further discloses a preparation method of the nitrilase mutant. The nitrilase mutant has the advantages that compared with AaNIT, the nitrilase mutant is greatly improved in activity and stereoselectivity, and when a crude extract or engineering bacterium whole cells of the nitrilase are used for catalysis, the reaction enzyme activity and stereoselectivity are still kept at a high level. Compared with a parent, the nitrilase mutant disclosed by the invention has the advantages that the activity is improved by 3.8 times, the stereoselectivity is improved by 10.3 times, and a foundation is laid for synthesizing (S)-2-(4-nitrophenyl) butyric acid by an industrial enzyme method.