CN117330755B - Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence - Google Patents

Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence Download PDF

Info

Publication number
CN117330755B
CN117330755B CN202311081225.XA CN202311081225A CN117330755B CN 117330755 B CN117330755 B CN 117330755B CN 202311081225 A CN202311081225 A CN 202311081225A CN 117330755 B CN117330755 B CN 117330755B
Authority
CN
China
Prior art keywords
dna
protein
luciferase
nano
target protein
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202311081225.XA
Other languages
Chinese (zh)
Other versions
CN117330755A (en
Inventor
吴绍文
晏石娟
王凤华
张文洋
黄文洁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Agro-Biological Gene Research Center Guangdong Academy Of Agricultural Sciences
Original Assignee
Agro-Biological Gene Research Center Guangdong Academy Of Agricultural Sciences
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Agro-Biological Gene Research Center Guangdong Academy Of Agricultural Sciences filed Critical Agro-Biological Gene Research Center Guangdong Academy Of Agricultural Sciences
Priority to CN202311081225.XA priority Critical patent/CN117330755B/en
Publication of CN117330755A publication Critical patent/CN117330755A/en
Application granted granted Critical
Publication of CN117330755B publication Critical patent/CN117330755B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/68—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving proteins, peptides or amino acids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/5308—Immunoassay; Biospecific binding assay; Materials therefor for analytes not provided for elsewhere, e.g. nucleic acids, uric acid, worms, mites
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/531—Production of immunochemical test materials
    • G01N33/532—Production of labelled immunochemicals
    • G01N33/535—Production of labelled immunochemicals with enzyme label or co-enzymes, co-factors, enzyme inhibitors or enzyme substrates

Abstract

The invention discloses a method for quantitatively detecting DNA-protein interaction based on enzyme catalysis biological fluorescence. The method is to fuse and express the nano luciferase and the target protein, and to detect the binding affinity of the protein and the DNA after hybridization with the coated DNA. The method provided by the invention can detect and analyze the interaction of DNA-protein conveniently, with low cost and high efficiency, thereby better meeting the requirement of protein and DNA binding affinity determination.

Description

Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence
Technical Field
The application relates to the field of biotechnology, in particular to a method for quantitatively detecting DNA-protein interaction based on enzyme catalysis biological fluorescence.
Background
Protein binding to DNA is one of the key steps in many biological regulatory mechanisms. By measuring the binding dissociation constant, the affinity and specificity between the protein and the DNA can be revealed. This helps us understand the molecular mechanisms of life processes such as gene expression regulation, DNA repair, chromatin structure, etc. There are various methods for quantitative determination of DNA and protein binding dissociation constants, mainly including calorimetric method (Isothermal Titration Calorimetry, ITC), surface plasmon resonance (Surface Plasmon Resonance, SPR), fluorescence resonance energy transfer (Fluorescence Resonance Energy Transfer, FRET), enzyme-linked immunosorbent assay (Enzyme-Linked Immunoassay, ELISA) and the like. The ITC and SPR require special and expensive equipment, the FRET experiment requires fluorescent labeling, and the distance between the protein and the labeling site of DNA is required to meet the detection requirement, so that the technical difficulty is high. The enzyme-linked immunoassay (ELISA) is a method commonly used in the field of biological analysis, is relatively easier to realize, and has relatively lower detection cost.
The basic of the enzyme-linked immunoassay technology is the immobilization of antigen or antibody and the enzyme labeling of antibody or antigen, and the basic principle comprises: the antibody (antigen) is adsorbed on the outer surface of the solid phase carrier, and the immunocompetence of the antibody (antigen) is maintained; antibodies (antigens) can be linked to enzymes by covalent bonds to form enzyme complexes and maintain the original immunological and enzymatic activities; after binding of the enzyme complex to the corresponding antibody (antigen), the test results can be determined based on the color change after addition of the substrate. The technology has the advantages of simple and convenient operation, effectiveness, strong specificity, high sensitivity, no need of expensive instruments and equipment and the like, and has been widely applied to various aspects such as drug residues, heavy metal pollution, biotoxin, food additive detection and the like.
In the traditional ELISA technology, in the experiment of detecting DNA-protein interaction, biotin marked DNA is required to be coated on a streptavidin modified ELISA plate, then a specific label on the primary antibody is used for identifying protein, and then a secondary ELISA antibody is used for color development, so that the steps are complicated, the stability is poor, the primary antibody and the secondary ELISA antibody are difficult to obtain through a low-cost prokaryotic expression system, and the cost is still high.
Disclosure of Invention
In view of these drawbacks, we have invented a method for quantitative determination of DNA-protein interactions based on enzyme-catalyzed bioluminescence.
The invention provides a method for detecting DNA-protein interaction, which is to hybridize luciferase-target protein with coated DNA and determine the binding affinity of the protein and the DNA.
Preferably, the nucleotide sequence of the luciferase and the nucleotide sequence of the target protein are constructed on the same expression vector.
Preferably, the luciferase is nano luciferase, and the amino acid sequence of the nano luciferase is shown in positions 1-170 of SEQ ID NO. 1.
Preferably, the DNA is double stranded DNA.
Preferably, the binding affinity of the assay protein to DNA is an assay DNA and protein binding dissociation constant.
Preferably, the method comprises the following steps:
(1) Constructing a nano luciferase-target protein expression plasmid, and expressing and purifying to obtain fusion protein;
(2) Synthesizing and coating double-stranded DNA;
(3) Hybridizing the fusion protein of step (1) with the DNA coated in step (2);
(4) The binding affinity of the protein to DNA was determined.
Preferably, the amino acid sequence of the nano luciferase-target protein is shown as SEQ ID NO.1, and the sequence of the DNA is shown as SEQ ID NO.2 or SEQ ID NO. 3. The 1 st to 170 th positions of SEQ ID NO.1 are nano luciferase (Nluc), the 171 st to 182 th positions are linker, and the 182 th to 273 th positions are target protein AflRN.
Preferably, the nano luciferase-target protein expression plasmid is formed by constructing a nucleotide sequence of the nano luciferase and a nucleotide sequence of the target protein on the same expression vector PET.M.3C, and the expression is expressed in escherichia coli.
Preferably, the step of determining the binding affinity of the protein to DNA is determining the binding dissociation constant of the DNA and the protein.
Preferably, the sample concentration of the nano-luciferase-target protein is 0.32-20. Mu.M, and the coated DNA concentration is 1-5. Mu.M.
The invention has the advantages that:
the method provided by the invention can detect and analyze the interaction of DNA-protein conveniently, with low cost and high efficiency, thereby better meeting the requirement of protein and DNA binding affinity determination.
Drawings
FIG. 1 is a DNA coating and protein binding capacity test.
FIG. 2 is a comparison of DNA-protein binding affinities based on enzyme bioluminescence detection and isothermal calorimetric assays.
Detailed Description
In order to realize the technical invention, the invention adopts the following technical scheme:
corresponding DNA and amino acid sequences were looked up from NCBI database or literature depending on the protein species. The DNA and protein sequences were submitted to the gene synthesis company for synthesis. Thus constructing nano luciferase-target protein expression plasmid, expressing and purifying fusion protein and using target DNA sequence to establish analysis method based on enzyme catalysis biological fluorescence quantitative detection protein-DNA binding affinity.
The following examples are further illustrative of the invention and are not intended to be limiting thereof.
Example 1: construction of nano luciferase-target protein Nluc-AflRN expression plasmid
The nucleotide sequence of the nano-luciferase-target protein Nluc-AflRN (shown as SEQ ID NO. 4) was synthesized by commercial company (Soy silicon based biotechnology Co., ltd.) and genes were inserted into a prokaryotic expression vector (PET.M.3C, soy silicon based biotechnology Co., ltd., cat. No. PET.M.3C: G080-2) using BamH1 and EcoR1 cleavage sites to obtain recombinant plasmids. E.coli DH5 alpha competent cells were transformed with the recombinant plasmid, plated on LB medium plates containing 100. Mu.g/mL ampicillin resistance, and cultured at 37℃for 16 hours to obtain single colonies with uniform growth. And (3) picking the monoclonal, respectively culturing the monoclonal at 37 ℃ in 50mL of culture medium overnight, carrying out colony PCR verification on the monoclonal by adopting the general primers T7 and T7-ter of the pet.M.3C vector, extracting plasmids after positive cloning is obtained, and carrying out sequencing verification. The recombinant plasmid after sequencing verification is used for subsequent experiments.
Example 2: expression of the protein of interest
The recombinant plasmid sequenced correctly in example 1 was transformed into E.coli BL21 competent cells. 1. Mu.L of recombinant plasmid was added to competent cells, and the mixture was subjected to ice bath for about 30 minutes, followed by heat shock at 42℃for 90 seconds and ice bath for 5 minutes. 200. Mu.L of amp (100. Mu.g/mL, the same applies hereinafter) resistant LB medium was added, and the mixture was incubated at 220rpm and 37℃for about one hour, and the bacterial solution was spread on an amp resistant LB medium plate and incubated overnight at 37℃in a constant temperature incubator.
Single colonies with good conditions on the resistance plates were picked and inoculated into 7mL of LB medium containing amp resistance, and cultured overnight at 220rpm and 37 ℃. Transferring the cultured bacterial liquid into 1L LB medium with amp resistance, 220rpm and 37Culturing at a temperature of about DEG C to OD 600 About 0.8. The culture medium was cooled to 16℃by standing at 4-8℃for a period of time, and protein expression was induced by adding IPTG to a final concentration of about 0.3mM, and by induction at 220rpm at 16℃for 18 hours.
Example 3: purification of proteins of interest
The induced bacterial liquid was centrifuged at 4000rpm at 4℃for 15min, and the supernatant was discarded, and 25mL of lysis buffer (20 mM Tris-HCl,100mM NaCl,5mM Imidazole,10. Mu.M ZnCl) 2 pH 7.9) for purification or short-term storage in-20deg.C refrigerator, long-term storage in-80deg.C refrigerator.
To the resuspended bacterial liquid, 150. Mu.L of 100mM protease inhibitor PMSF (100 mM in isopropanol) was added, and the cells were disrupted by ultrasonic waves of 20KHz,130W, 5 seconds of ultrasonic waves for 15 minutes.
The crushed bacterial liquid is transferred into a round bottom centrifuge tube, and the bacterial liquid is centrifuged at 12000rpm for 30min at 4 ℃.
Transferring the supernatant after centrifugation to a new centrifuge tube, adding 2M magnesium sulfate solution to a final concentration of 2mM, mixing, adding 125 mu L of 0.2mg/mL DNase, and performing enzymolysis in ice for 30min after mixing, so as to remove nonspecific DNA possibly combined by the DNA binding protein in the purification process.
Pouring the obtained supernatant into an Ni affinity column at 4 ℃, fully stirring and uniformly mixing, and then stirring and uniformly mixing every 10 minutes to fully combine the protein and the affinity column, wherein the total time is about half an hour.
After binding for a period of time, the supernatant was flowed down with a wash buffer (20 mM Tris-HCl,1M NaCl,20mM Imidazole,10. Mu.M ZnCl) 2 pH 7.9) was thoroughly stirred and soaked for 5min, then the valve was opened to flow down the liquid, and the affinity column was rinsed 2 times
With 7mL of the buffer for resolution (20 mM Tris-HCl,500mM NaCl,1M Imidazole,10. Mu.M ZnCl) 2 pH 7.9) for 10 minutes and collecting the eluate
SDS-PAGE identifies protein expression and further purification by gel filtration chromatography (AKTA protein purifier, hiLoad 16/600Superdex 75pg column) gives the Nluc-AflRN protein.
Adding the Nluc-AflRN protein solution to be concentrated into a 3kDa concentration tube, and centrifuging at 4 ℃ and 4000 rpm; concentrating the protein to the required concentration (> 100 mu M), and packaging into EP tubes; centrifuging at 13000rpm at 4deg.C for 5min, collecting supernatant, quick freezing with liquid nitrogen, and storing at-80deg.C.
Example 4: preparation of color developing solution and substrate for testing enzyme activity
S1, buffer solution preparation
S2, substrate configuration: 250 μg of coelengterazine-H was dissolved in 613 μl of solvent (85% methanol, 15% glycerol) to give a 1mM final concentration mother liquor.
S3, color development liquid (100 mu L)
Example 5: DNA coating test
The DNA coating solution was prepared by using 42% ammonium sulfate, 0.6% sodium chloride, 57.4% water and pH 6.1 in mass ratio, and filtering and sterilizing the solution. Synthesis of forward and reverse DNA sequences: 5'-ACCGACTCTCGGACAGCGAGGCAGACCG-3',5'-CGGTCTGCCTCGCTGTCCGAGAGTCGGT-3'; the forward and reverse DNA sequences were resuspended in PBS buffer, pH 6.8 to a final concentration of 400. Mu.M, respectively, and annealed to extend into double stranded DNA according to the following procedure:
the synthesized double-stranded DNA was subjected to gradient dilution with a DNA coating solution and mixed uniformly at concentrations of 0. Mu.M, 0.5. Mu.M, 1. Mu.M, 1.5. Mu.M, 2. Mu.M, 2.5. Mu.M, 3. Mu.M, 4. Mu.M, 5. Mu.M, respectively. Measuring absorbance of each DNA dilution, i.e. DNA amount before incubation, using ultra-micro UV-visible spectrophotometer, adding 100 μl/well of the mixture into corresponding well of 96-well plate, taking a sample size of 21×13×13 (cm) 3 ) The foam box is filled with half of water and a small storage rack, the pore plate is carefully placed on the storage rack in the foam box, the pore plate can not contact the water surface, and the foam box cover is coveredIncubate overnight at room temperature. After overnight incubation, the amount of DNA in the solution was determined using an ultra-micro uv-vis spectrophotometer and the amount of DNA after incubation was subtracted from the amount of DNA before incubation to give the amount of DNA bound into the well plate.
The liquid in the wells was discarded and the microwell plates were washed once with PBS buffer (pH 6.8).
In a fume hood, 100. Mu.L of 0.25% (v/v) glutaraldehyde was added to the microwell plate for 2 hours.
0.25% glutaraldehyde was discarded and treated with 100. Mu. L0.2M glycine hydrochloride solution (pH 2.8) for 15min.
The glycine hydrochloride solution (pH 2.8) was discarded and the microplate was washed 3 times with PBS buffer (pH 6.8).
100. Mu.L of PBS buffer (pH 6.8) containing 3% BSA by volume was added to each well for blocking, and blocking was performed at room temperature for 1 hour.
The solution from the previous step was removed and washed 5 times with Tween-PBS (pH 6.8) buffer.
Hybridization experiments were performed: 200. Mu.L of the Nluc-AflRN protein sample prepared in example 3 (10. Mu.M) was added to a corresponding well plate, incubated at 37℃for 30min, the well plate was carefully washed five times with Tween-PBS (pH 6.8) buffer, the well plate was not allowed to dry during the washing process, 100. Mu.L of a chromogenic solution containing the luciferase substrate coelenergazine-H was added, and the intensity of the bioluminescence signal was immediately detected using an enzyme-labeled instrument.
The results (as in FIG. 1) show that the amount of bound DNA in the well plate increases with increasing concentration, and that the bioluminescence intensity increases with increasing concentration of DNA after addition of the luciferase fusion protein, consistent with a gradual increase in the amount of coated DNA in the well plate. Wherein the concentration of the coated DNA was 7.8 ng/. Mu.L (about 0.5. Mu.M) at a concentration of 2. Mu.M by incubation, and the fluorescence value was about 70% of the maximum DNA coating concentration. Under this condition, the bioluminescence intensity is high, the concentration of the coated DNA is far lower than that of the fusion protein, and the coated DNA is suitable for measuring the binding dissociation constant and is used for subsequent experimental tests.
Example 6: determination of DNA and protein binding dissociation constant
The synthesized double-stranded DNA was subjected to gradient dilution with a DNA coating solution to a concentration of 2. Mu.M, andmixing well. The mixture was added to the corresponding well plate at 100. Mu.L per well, and a size of 21X 13 (cm) 3 ) The foam box of (2) is filled with half of water and a small rack, the pore plate containing the DNA solution is carefully placed on the rack in the foam box, the pore plate can not contact the water surface, the cover of the foam box is covered, and the solution is incubated overnight at room temperature.
The liquid in the wells was discarded and the microwell plates were washed once with PBS buffer (pH 6.8).
In a fume hood, 100. Mu.L of 0.25% (v/v) glutaraldehyde was added to the microwell plate for 2 hours.
Discard 0.25% glutaraldehyde and add 100 μl0.2M glycine hydrochloride solution (pH 2.8) for 15min.
The glycine hydrochloride solution (pH 2.8) was discarded and the microplate was washed 3 times with PBS buffer (pH 6.8).
100. Mu.L of PBS buffer (pH 6.8) containing 3% BSA by volume was added to each well for blocking, and blocking was performed at room temperature for 1 hour.
The solution from the previous step was removed and washed 5 times with Tween-PBS (pH 6.8) buffer.
Hybridization experiments were performed: samples of Nluc-AflRN protein were diluted in a gradient of 0. Mu.M, 0.16. Mu.M, 0.32. Mu.M, 0.64. Mu.M, 1.25. Mu.M, 2.5. Mu.M, 5. Mu.M, 10. Mu.M, 20. Mu.M using PBS buffer (pH 6.8), the protein samples were added to corresponding well plates (200. Mu.L per well) and incubated at 37℃for 30min, the well plates were carefully washed five times with Tween-PBS buffer (pH 6.8), the well plates were not allowed to dry during washing, 100. Mu.L of a chromogenic solution containing the luciferase substrate coelenterazine-H was added, and the bioluminescence signal intensity was immediately detected using an ELISA reader.
Note that: in carrying out the experimental test of the present invention, the concentration of the DNA to be coated is selected according to the binding capacity between the protein and the DNA; when in coating, the preservative film is coated on the pore plate, so that the coating efficiency is improved; the glutaraldehyde concentration used in the experiment is not too high, otherwise, the experiment result is interfered; increasing the BSA blocking time has a certain improvement on the binding efficiency of DNA and protein.
The results (as in FIG. 2A) indicate that as the concentration of the luciferase-target protein fusion protein Nluc-AflRN increases, it growsThe luminous intensity of the substance increases and gradually reaches saturation. Using the single-point fitting equation: y=rmax X/(K) D +X)
Wherein Y is the intensity of bioluminescence, X is the concentration of luciferase-target protein fusion protein, rmax is the maximum bioluminescence intensity, and the binding dissociation constant is 1.34 mu M.
Example 7: detection method based on enzyme-linked biological fluorescence (ELISA) by using isothermal calorimetric (ITC) experiment
ITC experiments were performed on a Nano ITC calorimeter (ta instruments). The sample zone temperature was set at 16 ℃. The DNA and protein samples were used at concentrations of 0.5mM and 0.05mM, respectively. During titration, high concentration DNA in the needle was injected into the pool at 1.5 μl intervals of 1 minute and 30 seconds each time with low concentration of protein and the endothermic heat of reaction was measured, and titration data was analyzed using nanoAnyze program.
The results (as in FIG. 2B) show that the binding dissociation constant of the target protein and DNA of the ITC assay is 1.56. Mu.M, which is similar to that obtained based on enzyme-catalyzed bioluminescence detection, and the accuracy of the method is verified.
SEQ ID NO.1 (nano-luciferase-target protein Nluc-AflRN)
VFTLEDFVGDWRQTAGYNLDQVLEQGGVSSLFQNLGVSVTPIQRIVLSGENGLKIDIHVIIPYEGLSGDQMGQIEKIFKVVYPVDDHHFKVILHYGTLVIDGVTPNMIDYFGRPYEGIAVFDGKKITVTGTLWNGNKIIDERLINPDGSLLFRVTINGVTGWRLCERILAGGSGGSGGSGGSRASPGPIRSSQTRRARKLRDSCTSCASSKVRCTKEKPACARCIERGLACQYMVSKRMGRNPRAPSPLDSTRRPSESLPSAGSEQGLPAHNTSEQ ID NO.2
ACCGACTCTCGGACAGCGAGGCAGACCG
SEQ ID NO.3
CGGTCTGCCTCGCTGTCCGAGAGTCGGT
SEQ ID NO.4 (Nluc-AflRN nucleotide sequence)
GTGTTCACTCTGGAAGATTTCGTGGGTGATTGGCGCCAGACTGCAGGTTACAATCTGGATCAGGTTCTGGAACAGGGCGGCGTCTCCTCTCTGTTCCAAAACCTGGGCGTTTCTGTTACTCCGATCCAACGTATCGTCCTGTCTGGTGAAAACGGCCTGAAAATTGACATCCACGTGATTATTCCGTACGAAGGTCTGAGCGGTGATCAGATGGGCCAGATTGAAAAAATTTTCAAGGTTGTTTATCCGGTTGACGACCACCACTTTAAAGTTATCCTGCACTATGGTACGCTGGTTATCGACGGTGTCACCCCGAACATGATCGATTATTTTGGTCGTCCGTACGAAGGTATCGCGGTTTTCGACGGCAAAAAAATCACGGTGACCGGCACCCTGTGGAACGGTAACAAAATCATCGACGAACGTCTGATCAACCCGGACGGTTCCCTGCTGTTCCGTGTTACCATCAACGGCGTCACCGGTTGGCGTCTGTGCGAACGTATCCTGGCGGGTGGTTCTGGCGGCTCCGGCGGTAGCGGTGGCTCTCGGGCATCTCCCGGACCGATCCGTTCCTCCCAGACTCGCCGCGCCCGAAAGCTCCGGGATAGCTGTACGAGTTGTGCCAGTTCAAAAGTGCGATGCACCAAGGAGAAACCGGCCTGTGCTCGGTGTATCGAACGTGGTCTTGCCTGTCAATACATGGTCTCCAAGCGGATGGGCCGCAATCCGCGCGCTCCCAGTCCCCTTGATTCAACTCGGCGACCATCAGAGAGTCTCCCTTCAGCCGGGTCGGAACAGGGACTTCCGGCGCACAACACG。

Claims (4)

1. A method for detecting DNA-protein interactions, characterized in that for hybridizing a luciferase-target protein to coated DNA, the binding affinity of the protein to the DNA is determined, comprising the steps of:
(1) Constructing a nano luciferase-target protein expression plasmid, and expressing and purifying to obtain fusion protein;
(2) Synthesizing and coating double-stranded DNA;
(3) Hybridizing the fusion protein of step (1) with the DNA coated in step (2);
(4) Determining the binding affinity of the protein to DNA;
the amino acid sequence of the nano luciferase-target protein is shown as SEQ ID NO.1, and the sequence of the DNA is shown as SEQ ID NO.2 or SEQ ID NO. 3;
the double-stranded DNA is coated by subjecting the synthesized double-stranded DNA to gradient dilution with a DNA coating solution to a concentration of 2. Mu.M, mixing, adding the mixture into corresponding pore plate at a volume of 100 μl per well, and taking a size of 21×13×13× cm 3 The foam box of (2) is filled with half of water and a small rack, the pore plate containing the DNA solution is carefully placed on the rack in the foam box, the pore plate can not contact the water surface, the cover of the foam box is covered, and the solution is incubated overnight at room temperature.
2. The method of claim 1, wherein the nucleotide sequence of the luciferase and the nucleotide sequence of the protein of interest are constructed on the same expression vector.
3. The method of claim 1, wherein determining the binding affinity of the protein to DNA is determining the binding dissociation constant of the DNA and the protein.
4. The method according to claim 1, wherein the nano-luciferase-target protein expression plasmid is obtained by constructing a nucleotide sequence of nano-luciferase and a nucleotide sequence of target protein on the same expression vector pet.m.3c, and the expression is in escherichia coli.
CN202311081225.XA 2023-08-25 2023-08-25 Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence Active CN117330755B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311081225.XA CN117330755B (en) 2023-08-25 2023-08-25 Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311081225.XA CN117330755B (en) 2023-08-25 2023-08-25 Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence

Publications (2)

Publication Number Publication Date
CN117330755A CN117330755A (en) 2024-01-02
CN117330755B true CN117330755B (en) 2024-03-26

Family

ID=89278015

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311081225.XA Active CN117330755B (en) 2023-08-25 2023-08-25 Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence

Country Status (1)

Country Link
CN (1) CN117330755B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102686726A (en) * 2009-11-27 2012-09-19 巴斯夫植物科学有限公司 Chimeric endonucleases and uses thereof
CN106916795A (en) * 2015-12-24 2017-07-04 中国科学院深圳先进技术研究院 A kind of adjustable luciferase segmentation fusion protein, its preparation method and application
CN109612981A (en) * 2012-12-12 2019-04-12 普洛麦格公司 It is combined using the cell target that intracellular biological luminescence resonance energy shifts identification bioactivator
CN112567028A (en) * 2018-06-12 2021-03-26 普洛麦格公司 Multi-part luciferases
CN112840022A (en) * 2018-08-14 2021-05-25 哈佛大学校长及研究员协会 In vitro detection of nucleic acids

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160355875A1 (en) * 2013-10-11 2016-12-08 Cellectis Methods and kits for detecting nucleic acid sequences of interest using dna-binding protein domain

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102686726A (en) * 2009-11-27 2012-09-19 巴斯夫植物科学有限公司 Chimeric endonucleases and uses thereof
CN105384827A (en) * 2009-11-27 2016-03-09 巴斯夫植物科学有限公司 Chimeric endonucleases and uses thereof
CN109612981A (en) * 2012-12-12 2019-04-12 普洛麦格公司 It is combined using the cell target that intracellular biological luminescence resonance energy shifts identification bioactivator
CN106916795A (en) * 2015-12-24 2017-07-04 中国科学院深圳先进技术研究院 A kind of adjustable luciferase segmentation fusion protein, its preparation method and application
CN112567028A (en) * 2018-06-12 2021-03-26 普洛麦格公司 Multi-part luciferases
CN112840022A (en) * 2018-08-14 2021-05-25 哈佛大学校长及研究员协会 In vitro detection of nucleic acids

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Development of a Quantitative BRET Affinity Assay for Nucleic Acid-Protein Interactions;Timothy A. Vickers 等;PLOS ONE;20160829;第11卷(第8期);摘要，第2-14页，图1-7 *

Also Published As

Publication number Publication date
CN117330755A (en) 2024-01-02

Similar Documents

Publication Publication Date Title
JP4719403B2 (en) Functional protein array
EA019664B1 (en) Detection of cannabis use
CN113583996B (en) Bst DNA polymerase recombinant mutant, coding DNA thereof and ultra-fast magnetic bead LAMP detection method
WO2001062968A2 (en) Mutant nucleic binding enzymes and use thereof in diagnostic, detection and purification methods
EP0634018A1 (en) Method of detecting microorganisms
CN117330755B (en) Method for quantitatively detecting DNA-protein interaction based on enzyme-catalyzed biological fluorescence
CN108866060B (en) Nucleic acid aptamer specifically binding to crustacean arginine kinase, kit and detection method
CN113388037B (en) Preparation and application of specific recognition fenitrothion nano antibody
CN113307877B (en) Preparation and application of nano antibody capable of simultaneously recognizing fenitrothion and methyl parathion
JP5419138B2 (en) Detection method of detection object and detection kit used therefor
CN111393510B (en) African swine fever virus recombinant antigen and application thereof
US6509383B1 (en) Methods and compositions for screening cloned proteins
CN117347621B (en) Method for detecting aflatoxin B1 by using protein mimic antigen-nano antibody
CN111273005A (en) Enzyme linked immunosorbent assay kit and method for detecting toxoplasma gondii IgG antibody
CN112280829A (en) Kit, sample marking method and single cell sequencing method
CN110615846B (en) Bifunctional protein with IgG (immunoglobulin G) binding activity and biotin binding activity and ELISA (enzyme-linked immunosorbent assay) kit thereof
CN109576298A (en) The method for improving unnatural amino acid and introducing protein efficiency is handled using Cell Permeabilization
CN117362447B (en) Bioluminescence enzyme-linked immunoassay method based on protein coupled polymer
Schofield et al. Sequencing and affinity determination of antigen-specific B lymphocytes from peripheral blood
CN114773462B (en) Recombinant single-chain antibody for detecting bovine CRP protein and application thereof
EP0405592A2 (en) A method for detection of nucleic acid and reagents for their detection
US20220243255A1 (en) Molecular glue screening assays and methods for practicing same
RU2778251C2 (en) Recombinant chimeric protein consisting of large extracellular loop of human cd81 receptor and streptavidin
CN108396029B (en) A group of oligonucleotide aptamers capable of specifically recognizing Escherichia coli O157H 7 in different growth stages
White et al. Expression immunoassay based on antibodies labeled with a deoxyribonucleic acid fragment encoding the α-peptide of β-galactosidase

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant