126 results about "Substrate specificity" patented technology

The invention discloses a glycosyl transferase mutant and an application of the glycosyl transferase mutant in synthesis of rebaudioside. According to the invention, single-point mutation and multi-point mutation are carried out on the basis of a glycosyl transferase amino acid sequence as shown in SEQ ID NO: 1, and a mutant with improved catalytic activity is obtained. The catalytic activity, the substrate specificity and / or the substrate specificity of the glycosyl transferase mutant are / is changed, and the catalytic activity of enzyme to a specific substrate can be remarkably improved by mutation at a specific site. And carrying out induced expression and protein purification on the obtained mutation sequence to obtain the mutant enzyme. The mutant enzyme is used as a catalyst, and UDPG is used as a glycosyl donor, so that the catalytic reaction efficiency of substrates such as stevioside ST, rebaudioside A (RebA) and rebaudioside D (RebD) can be obviously improved. According to the glycosyl transferase UGT76G1 mutant constructed by the research, the catalytic activity of the glycosyl transferase UGT76G1 mutant is improved, and efficient production of rebaudioside M is realized by optimizing a reaction system.

The invention provides a keto-alcohol acid reductoisomerase mutant and application of the keto-alcohol acid reductoisomerase mutant in construction of genetically engineered bacteria for high yield of D-pantothenic acid. In order to solve the technical problem that in the prior art, the yield of D-pantothenic acid synthesized through microbial fermentation is not high, semi-rational design of enzyme is adopted, and a keto-alcohol acid reductoisomerase mutant with substrate specificity is obtained and applied to construction of genetically engineered bacteria for high yield of D-pantothenic acid. According to the invention, a genetically engineered bacterium with high yield of D-pantothenic acid is constructed by utilizing the keto-alcohol acid reductoisomerase mutant through a CRISPR-Cas9 gene editing technology, so that the yield of D-pantothenic acid is increased by about 12.04%, and compared with an original strain, the valine accumulation amount in obtained fermentation liquor is almost unchanged compared with that of a control, and the yield of D-pantothenic acid is greatly improved. However, the accumulation of branched chain amino acid isoleucine is less, so that the modification of the substrate specificity of the keto-alcohol acid reductoisomerase is achieved.

The invention discloses a method for regulating the transport activity of a strain to 1-aminocyclopropane-1-carboxylic acid, and relates to the technical field of bioengineering. The method for regulating and controlling the transport activity of the strain to 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues and the tolerance of the strain to the 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues, disclosed by the invention, comprises the step of transferring a LeuE gene into escherichia coli to obtain an escherichia coli recombinant strain with corresponding functions. The invention discloses the application of the LeuE protein and the LeuE gene in regulating and controlling the transport activity of escherichia coli to the 1-aminocyclopropane-1-carboxylic acid and / or methionine analogue and the tolerance of escherichia coli to the 1-aminocyclopropane-1-carboxylic acid and / or methionine analogue for the first time. The invention discloses that LeuE is an optimal candidate gene for constructing ACC synthetic bacteria for the first time, and the substrate specific transport of the LeuE meets the aim of enhancing the ACC tolerance of cells without influencing precursor supply.

The invention discloses a sample concentration detection method, a standard curve group establishment method, a matrix specificity standard curve optimization method, a standard curve group establishment device and an immunity analyzer, and belongs to the field of diagnostic analysis. Acquiring matrix information of a to-be-detected sample; selecting a matrix specificity standard curve corresponding to the matrix of the sample to be detected; and detecting the sample and calculating the concentration of the analyte in the sample to be detected by using a matrix specificity standard curve selected from a plurality of standard curve groups of which the specificity corresponds to different matrixes. The corresponding substrate specificity standard curves are configured for various types of substrates in advance, and when a detection task is carried out, the corresponding substrate specificity standard curves can be selected and called, so that the detection is more targeted, the substrate effect caused by using a general standard curve can be avoided, the substrate effect can be reduced, the implementation operation is simpler, and the detection efficiency is improved. And the working time of detection personnel can be remarkably saved, and the detection cost is effectively reduced.

The invention discloses a method for detecting antioxidants and polyphenols in food by constructing a colorimetric sensing array based on monatomic iron nano-enzyme, and belongs to the field of nanotechnology and colorimetric sensing. The traditional monatomic nano enzyme shows limited enzyme-like activity and substrate specificity, and is difficult to meet the comprehensive requirements of detecting various antioxidants and polyphenols in food. In the research, a novel nano-enzyme system (sdsFeN (at) G) of monatomic iron nano-enzyme is developed. The SdsFeN (at) G shows excellent enzymatic activity, and a three-channel colorimetric sensing array is constructed by utilizing inhibition of different antioxidants and polyphenols on oxidation of three chromogenic substrates, so that simple, convenient and reliable identification and detection of five substances (tert-butylhydroquinone, butylated hydroxyanisole, propyl gallate, catechol and hydroquinone) in food are realized.

The invention relates to beta-1, 4-glucanase and application thereof, and belongs to the technical field of biology. A novel beta-1, 4-glucanase is screened and identified in Pleurotus tuber-regium, and the beta-1, 4-glucanase has wide substrate specificity, can specifically hydrolyze beta-glucan (such as sodium carboxymethyl cellulose) containing beta-1, 4 glucosidic bonds, and can hydrolyze beta-glucan (such as sodium carboxymethyl cellulose) containing beta-1, 3-1, 4-glucanase) containing beta-1, 3-1, 4-glucanase. The beta-1, 4-glucanase disclosed by the invention can be used for preparing beta-glucan (such as barley beta-glucan and oat beta-glucan) containing beta-1, 3-1, 4 glucosidic bonds, so that the beta-1, 4-glucanase disclosed by the invention has good enzyme activity on the beta-glucan containing the beta-1, 4 glucosidic bonds and the beta-glucan containing the beta-1, 3-1, 4 glucosidic bonds. Besides, the enzyme activity of the beta-1, 4-glucanase disclosed by the invention can be kept at 70% or above under the condition that the pH value is 4.0-7.0, the enzyme activity of the beta-1, 4-glucanase can be kept at 88% or above under the temperature of 40 DEG C, and the beta-1, 4-glucanase has good stability.

The invention provides a keto-alcohol acid reductoisomerase mutant and application of the keto-alcohol acid reductoisomerase mutant in construction of genetically engineered bacteria for high yield of D-pantothenic acid. In order to solve the technical problem that in the prior art, the yield of D-pantothenic acid synthesized through microbial fermentation is not high, semi-rational design of enzyme is adopted, and a keto-alcohol acid reductoisomerase mutant with substrate specificity is obtained and applied to construction of genetically engineered bacteria for high yield of D-pantothenic acid. According to the invention, a genetically engineered bacterium with high yield of D-pantothenic acid is constructed by utilizing the keto-alcohol acid reductoisomerase mutant through a CRISPR-Cas9 gene editing technology, so that the yield of D-pantothenic acid is increased by about 12.04%, and compared with an original strain, the valine accumulation amount in obtained fermentation liquor is almost unchanged compared with that of a control, and the yield of D-pantothenic acid is greatly improved. However, the accumulation of branched chain amino acid isoleucine is less, so that the modification of the substrate specificity of the keto-alcohol acid reductoisomerase is achieved.

The invention discloses a D-psicose 6-phosphate phosphatase mutant and application of the D-psicose 6-phosphate phosphatase mutant in preparation of psicose, and belongs to the technical field of enzyme engineering. According to the invention, site-directed mutagenesis is carried out on an amino acid sequence of D-psicose 6-phosphate phosphatase A6PP, and a combined mutant I21V / Y73F / R115M / T180V / L203I / Q193E is constructed, so that the substrate specificity, the thermal stability and the catalytic activity of the combined mutant are all remarkably improved. The invention further provides application of the combined mutant in preparation of psicose through multi-enzyme cascade catalysis, 150 g / L of maltodextrin can be converted into 97.7 g / L of D-psicose, the conversion rate reaches 65.1%, and the application prospect of the combined mutant in the field of food is widened.

The invention discloses a 4-hydroxyphenylacetic acid 3-hydroxylase mutant and application thereof, recombinant expression plasmids and corresponding genetically engineered bacteria M214V, R290N and E294I are constructed by using genes for coding the mutants (EcHpaBM214V, EcHpaBR290N and EcHpaBE294I) and nucleotide sequences for coding EcHpaC genes respectively, and after the genetically engineered bacteria disclosed by the invention are subjected to shake flask fermentation in a 30mL M9Y culture medium containing 50mu g / mL chloramphenicol for 24 hours, the yield of the mutants is increased, and the yield of the mutants is increased. The yield of the tanshinol is 748.04 mg / L, 895.55 mg / L and 793.36 mg / L. The method breaks through the limitation that the substrate generated by the 4-hydroxyphenylacetic acid 3-hydroxylase through catalysis is poor in specificity and low in catalysis efficiency, and the yield of the tanshinol is high. The method has the advantages of being high in catalytic efficiency, simple in process and environmentally friendly.

The invention relates to a genetically modified cell, and belongs to the technical field of biological genetic engineering. The invention provides a genetically modified cell, which contains a heterologous nucleic acid sequence of an alpha-1, 3-fucosyltransferase polypeptide. The alpha-1, 3-fucosyltransferase polypeptide further comprises but is not limited to derived polypeptides M1-M21 of the polypeptide with the amino acid sequence as shown in SEQ ID NO: 1, and compared with the polypeptide as shown in SEQ ID NO: 1, the 3-FL catalytic synthesis capability of the derived polypeptides and the specificity of a catalytic substrate are both improved.

The invention relates to a UGT enzyme subtype substrate specificity prediction method and model. On the basis of a directional message passing neural network, graph structure characterization of a small molecule compound and features of specific protein binding sites of UGT enzyme are deeply fused, a bimodal prediction normal form of'molecule + protein binding sites' is designed, a deep learning model is constructed, conversion from compound center prediction to molecule-enzyme binding site comprehensive prediction is achieved, and the prediction accuracy is improved. And accurate classification prediction can be carried out on UGT enzyme substrates and non-substrates.

The invention provides a method for biosynthesizing menadione by using yarrowia lipolytica. The method is realized by constructing recombinant yarrowia lipolytica, and the construction method of the recombinant yarrowia lipolytica for synthesizing menadione comprises the following steps: intensively expressing a mevalonic acid pathway in the yarrowia lipolytica, and synthesizing menadione by introducing a synthesis pathway of heterologous geranyl and geranyl pyrophosphate. A sufficient isoprene side chain donor is provided for biosynthesis of menadione; on the basis, an aromatic isopentenyl transferase coding gene which is optimized by codons and has menadione substrate specificity is over-expressed in yarrowia lipolytica. The construction method of the yarrowia lipolytica for biosynthesis of menadione provided by the invention is simple to operate, the constructed yarrowia lipolytica can obtain a menadione product with relatively high concentration by taking commercially available menadione as a substrate, the biosynthesis steps are relatively short, and the yarrowia lipolytica has relatively high production and application values.

The invention discloses a carboxylic acid reductase DeCAR recombinant plasmid and application of the carboxylic acid reductase DeCAR recombinant plasmid in preparation of aldehyde spices, belongs to the technical field of bioengineering, and further provides a recombinant bacterium containing the recombinant plasmid, and the carboxylic acid reductase DeCAR is further produced by using the recombinant bacterium, or the recombinant bacterium is directly applied to production of the aldehyde spices. Compared with other biocatalysts for preparing aldehydes, the carboxylic acid reductase and the recombinant bacteria thereof provided by the invention have the advantages of wide substrate spectrum, high catalytic activity, strong substrate specificity and the like, and have wide application prospects in industrial application.

The invention relates to an inositol dehydrogenase mutant and application of the inositol dehydrogenase mutant in synthesis of D-chiral inositol. The invention discloses an inositol dehydrogenase mutant, nucleic acid for coding the inositol dehydrogenase mutant, a recombinant expression vector containing the nucleic acid, a recombinant expression transformant containing the recombinant expression vector, and a recombinant inositol dehydrogenase mutant catalyst. The invention also discloses an application of the inositol dehydrogenase mutant or the recombinant inositol dehydrogenase mutant catalyst in catalysis of biotransformation of inositol to synthesize D-chiral inositol. Compared with wild-type inositol dehydrogenase and literature reports, the inositol dehydrogenase disclosed by the invention has the characteristics of high enzyme activity and strong substrate specificity, and has the advantages of mild reaction conditions, small coenzyme addition amount, economy, environmental protection and the like when being used for catalytically preparing D-chiral inositol. Therefore, the inositol dehydrogenase mutant disclosed by the invention has a very good application prospect in actual production of the health care medicine D-chiral inositol.

The invention relates to peptides comprising or consisting of an amino acid sequence of 5 to 50 amino acids which has, in N- to C-terminus orientation, the amino acid sequence X5X6X7X8X9, where each of the five residues X represents an amino acid of a particular group, and / or the amino acid sequence has at least 85% sequence identity to one of the amino acid sequences mentioned in SEQ ID NOs: 1 - 17.

The invention relates to the technical field of biochemistry, in particular to an enzyme mutant and application thereof in preparation of conopeptide. According to the preparation method, a strategy of combining green chemistry and an enzyme method is adopted, seven tripeptide fragments are taken as raw materials, a conopeptide main chain is prepared through a liquid-phase synthesis method, and then enzymatic precise modification and synthesis are realized by utilizing a multiple directed evolution enzyme concerted catalysis system. Based on the efficient connection characteristic of a liquid-phase synthesis system and the high substrate specificity of an enzymatic system, the complex protection group operation in traditional solid-phase synthesis is effectively avoided, generation of by-products is remarkably reduced, meanwhile, fixed-point modification and precise assembly of a conopeptide main chain are achieved, and the application prospect is wide. And an efficient and green new path is provided for the continuous production of the cosmetic-grade high-purity conopeptide.

The invention provides chondroitin sulfate excision enzyme and application of the chondroitin sulfate excision enzyme in dermatan sulfate preparation. The amino acid sequence of the chondroitin sulfate excision enzyme is shown as SEQ ID NO: 3, and the chondroitin sulfate excision enzyme has broad-spectrum substrate specificity and can efficiently degrade hyaluronic acid and glycosaminoglycans such as chondroitin sulfate (A, C, E and D). The chondroitin sulfate excision enzyme can efficiently act on a substrate by virtue of a unique catalytic mechanism, so that efficient preparation of oligosaccharide and low-molecular-weight polysaccharide is realized, and the chondroitin sulfate excision enzyme can be particularly used for enzymatic preparation of dermatan sulfate. The chondroitin sulfate excision enzyme has efficient catalytic performance and unique treatment advantages, not only fills the technical blank in related fields, but also opens up a wide space for the development of carbohydrate chemicals in the fields of biological medicines, cosmetics, foods and the like.

The invention discloses a synthesis method of an amino-acid-based MOFs (Metal-Organic Frameworks) derived nano-enzyme, and relates to the technical field of nano-enzyme synthesis, the synthesis method of the amino-acid-based MOFs derived nano-enzyme comprises the following steps: step 1, selecting proper metal ions and organic ligands; step 2, ultrasonic dispersion; step 3, precipitate drying; and step 4, activating treatment of the nano enzyme. The MOFs-derived nano-enzyme with alkaline phosphatase activity is synthesized by taking natural amino acid as a ligand and one of ions of zirconium, copper and iron as a metal node and introducing defects by a method of adding an acidic regulator in synthesis, and the crystal structure of the nano-enzyme is not changed under the introduction of the defects, so that the alkaline phosphatase activity of the MOFs-derived nano-enzyme is improved. The MOFs-derived nano-enzyme has the advantages that the MOFs-derived nano-enzyme is modified, the catalytic hydrolysis activity of the MOFs-derived nano-enzyme on phosphate substrates is greatly improved, good substrate specificity is shown, the structure of the MOFs-derived nano-enzyme does not change after long-term incubation under acidic, alkaline and high-temperature conditions, and compared with natural enzyme, the MOFs-derived nano-enzyme has good stability, pH stability and reusability.

Describes herein is a lipase comprising a peptide sequence with at least 80% sequence similarity to SEQ ID NO: 3 and at least one mutation of SEQ ID NO: 3 selected from Q9, N11, A14, A23, K24, N26, A30, G31, A32, T35, R37, I40, S39, M58, G59, E87, G91, N92, I93, D96, D102, S105, G106, K108, D111, S115, N122, T123, T125, R133, A152, D158, G161, N162, F169, A180, A187, L193, R209, E210, S216, T223, T226, L227, G245, N248, P250, N251, T252, A256, L259, and any combinations thereof, or the peptide sequence comprises SEQ ID NO: 3. The lipase may be mixed with a fatty acid or a triacylglycerol and an alcohol under suitable conditions to produce a fatty acid ester. The substrate specificity of a Thermomyces dupontii lipase (TDL) may be enhanced by introducing a L259 mutation into a mature peptide sequence of TDL and expressing the L259 mutant.

The present invention discloses a genetically engineered bacterium expressing oligosaccharide debranching enzyme and its application, belonging to the technical field of microbial engineering. The present invention provides an oligosaccharide debranching enzyme with a specific base sequence, and successfully heterologously expresses the oligosaccharide debranching enzyme in Escherichia coli. By using the method of the present invention, the catalytic activity of the crude enzyme solution of the expressed oligosaccharide debranching enzyme can reach 258.83 U / mL. The oligosaccharide debranching enzyme provided by the present invention is a novel oligosaccharide debranching enzyme from a new source, which has not been reported before, has a high specific enzyme activity, and strong substrate specificity. The oligosaccharide debranching enzyme of the present invention can debranch short chain segments with DP<6 in maltodextrin, filling the blank in the substrate specificity of commonly used debranching enzymes at present, and has high potential application prospects in industrial fields such as starch sugar, resistant starch, beer production and ethanol fuel.

The present invention discloses a transaminase and its use in preparing optically pure chiral amines. The amino acid sequence of the transaminase of the present invention has one or more mutations at positions 65, 318, 399, 419, 426, 465, and 466 compared to SEQ ID NO: 1, wherein the mutation is an addition, deletion, or substitution of an amino acid residue. The present invention also discloses a nucleic acid molecule encoding the transaminase, a nucleic acid construct comprising the nucleic acid molecule, a recombinant vector, and a host cell. The present invention also discloses an enzyme preparation comprising the transaminase of the present invention. The present invention also discloses a method for preparing chiral amines using the transaminase. In the industrial production process of optically pure chiral amines, the enzyme provided by the present invention has advantages such as substrate specificity, enantiomeric selectivity, and high conversion rate. The method for preparing optically pure chiral amines provided by the present invention has high reaction efficiency, stereoselectivity, and yield.

The invention discloses polyethylene glycol terephthalate hydrolase PmPETase and application thereof.The hydrolase PmPETase is protein with the amino acid sequence shown in SEQ ID NO.1. An expression system suitable for the PmPETase is constructed, recombinase protein with catalytic activity is obtained, and the polyethylene glycol terephthalate hydrolase PmPETase can be used for preparing the polyethylene glycol terephthalate hydrolase PmPETase. The substrate specificity, the catalytic property and the potential plastic degradation capacity of the PET degrading enzyme are comprehensively analyzed, and a new theoretical basis and application reference are provided for development and utilization of the PET degrading enzyme and a high polymer material green treatment technology.

The present invention addresses the problem of providing an enzyme agent containing a novel aminopeptidase that exhibits substrate specificity different from that of conventional aminopeptidase. The present invention relates to an enzyme agent comprising, as an active ingredient, aminopeptidase comprising the amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 8 or an amino acid sequence equivalent thereto. Furthermore, the present invention relates to an enzyme agent which contains, as an active ingredient, an aminopeptidase that is derived from Aspergillus nidulans or Aspergillus oryzae and has the following physicochemical properties. (1) the optimum temperature is about 50 DEG C; and (2) the optimum pH is about 7-8. And (3) primer specificity: the primer has the highest specificity on L-alanine residues or L-lysine residues.

This invention provides a ketolic acid reductase mutant and its application in constructing genetically engineered bacteria that produce high levels of D-pantothenic acid. To address the technical problem of low D-pantothenic acid yield in existing microbial fermentation, this invention utilizes semi-rational enzyme design to obtain a substrate-specific ketolic acid reductase mutant, which is then applied to construct genetically engineered bacteria that produce high levels of D-pantothenic acid. Furthermore, this invention employs CRISPR-Cas9 gene editing technology to construct genetically engineered bacteria that produce high levels of D-pantothenic acid using the aforementioned ketolic acid reductase mutant, increasing D-pantothenic acid production by approximately 12.04%. Compared to the starting strain, the accumulation of valine in the fermentation broth remained almost unchanged compared to the control, but the accumulation of the branched-chain amino acid isoleucine was lower, achieving substrate-specific modification of the ketolic acid reductase.

The present invention discloses a method for regulating the transport activity of a strain to 1-aminocyclopropane-1-carboxylic acid, which relates to the technical field of bioengineering. The method for regulating the transport activity of a strain to 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues and the tolerance of the strain to 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues is to transfer the LeuE gene into Escherichia coli to obtain a recombinant Escherichia coli strain with corresponding functions. The present invention discloses for the first time the application of LeuE protein and LeuE gene in regulating the transport activity of Escherichia coli to 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues and the tolerance of Escherichia coli to 1-aminocyclopropane-1-carboxylic acid and / or methionine analogues. The present invention discloses for the first time that LeuE is the best candidate gene for constructing ACC-producing bacteria, and its substrate-specific transport meets the purpose of enhancing cell ACC tolerance without affecting precursor supply.

The invention discloses a method for detecting F26G enzyme activity based on an HPLC (High Performance Liquid Chromatography) technology, and belongs to the technical field of biological enzyme activity detection. According to the method, on the basis of the characteristic that furostanol saponin 26-O-beta-D-glucosidase (F26G) hydrolyzes furostanol saponin C-26 glucosyl, a detection system which takes furostanol saponin as a substrate and quantifies substrate consumption through an HPLC technology to calculate enzyme activity is established, the method has high substrate specificity, and compared with a pNPG method, the method has the advantages that the detection efficiency is high, and the detection cost is low. The method has the advantages of high sensitivity and high accuracy, can accurately eliminate the interference of other glucosidase in the system, overcomes the defects of poor specificity, low sensitivity and difficulty in accurate determination of the enzyme activity of the traditional pNPG method, provides a new method for accurate detection of the activity of the F26G enzyme in the medicinal materials, and provides technical support for quality monitoring of the medicinal materials and decoction pieces.

This invention discloses the application of arginine-depleted engineered bacteria for the treatment of soft tissue sarcomas, including preliminary validation, obtaining qualified engineered bacteria SGR1, obtaining drug compositions and regimens, experimental conclusions, and clinical application promotion. During use, clinical soft tissue sarcoma samples are collected, including undifferentiated pleomorphic sarcoma, synovial sarcoma, and liposarcoma. Immunohistochemistry (IHC) is used to detect ASS1 protein expression, qPCR is used to detect ASS1 gene transcription levels, and the proportion of ASS1 deletion / low expression is statistically analyzed. Arginine auxotrophic sarcoma subpopulations are confirmed based on literature. Cells are cultured in arginine-containing or arginine-free media, and cell viability, colony formation, cell cycle, and apoptosis are detected. The sensitivity of ASS1-deficient cells to arginine deprivation is verified, and therapeutic targets are identified. The enzyme activity, substrate specificity, and immunogenicity of human ARG I / II, mycoplasma ADI, and Pseudomonas ADI are compared. High-activity, low-immunogenic enzymes or enzyme combinations (such as human ARG I + microbial ADI) are selected, and site-directed mutagenesis or codon optimization is performed on microbial ADI to increase expression levels.

The present application relates to peptides comprising or consisting of an amino acid sequence of 5 to 50 amino acids which, in N- to C-terminal orientation, comprise the amino acid sequence X 5 X 6 X 7 X 8 X 9 wherein each of the five residues X represents an amino acid of a specific group, and / or the amino acid sequence has at least 85% sequence identity with one of the amino acid sequences listed in SEQ ID NOs: 1 - 17.

The purpose of the present invention is to provide: a plant having an increased yield of storage tissue; and a method for producing the plant. It was discovered that the yield of storage tissue in a plant can be increased by expressing, in the storage tissue of the plant, a sucrose synthase having a substrate specificity to adenosine diphosphate.

The invention discloses algin lyase Alg0392, DNA, recombinant plasmid, recombinant bacteria, application and an algin cracking preparation, and relates to the technical field of microorganisms, the amino acid sequence of the algin lyase Alg0392 is shown as SEQ ID No.1, the algin lyase Alg0392 has endonuclease activity and exonuclease activity, can degrade sodium alginate into monosaccharide, disaccharide and trisaccharide, and the algin lyase Alg0392 can be used for preparing the algin lyase Alg0392. Meanwhile, the method has substrate specificity on polymannuronic acid, and sodium alginate can be well and thoroughly degraded. In addition, dithiothreitol and beta-mercaptoethanol have a promoting effect on the enzyme activity of alginate lyase Alg0392, and can be prepared into an alginate lysing preparation to improve the degradation efficiency of an alginate substrate.