CN1385526A - Precursor gene of ink chest wasp aptoxin bematolysis peptide, its coded polypeptide and preparation process thereof - Google Patents

Abstract

The invention discloses a coding sequence of a hemolytic peptide precursor gene of Vespa japonica, its coded polypeptide and a preparation method. The protein encoded by the cDNA sequence is a homologue of the precursor of the Apis mellifera melitin hemolytic peptide, and has at least 70% homology with the nucleotide sequence from nucleotide 1 to 213 in SEQ ID No.5. The sequence encodes a polypeptide having the sequence shown in SEQ ID No.6. In addition, the vector containing the 130-213 nucleotide sequence of the hemolytic peptide precursor and the end of the hemolytic peptide precursor gene, the host cell, and the antibody related to the hemolytic peptide of the venom venom and the protein The preparation method of the polypeptide of the active Vespa venom hemolytic peptide and related antibodies. The invention lays a foundation for further studying the molecular action mechanism of the hemolytic peptide of the wasp venom and developing biomedicine, diagnostic reagents, biochemical reagents and biological insecticides related to the hemolytic peptide.

Description

Precursor gene of ink chest wasp aptoxin bematolysis peptide and encoded polypeptides thereof and preparation method

Technical field

The present invention relates to the genetically engineered field, relate in particular to ink chest wasp aptoxin bematolysis peptide precursor (Prepromelittin) gene and encoded polypeptides and preparation method.

Background technology

Apis mellifera (Apis mellifera) melittin (Melittin) is the ultimate constituent of apis mellifera bee venom; account for 40%～50% (Vol.3.New York:Academic of bee venom; 1971; 535), by sources and biochemical property, it is a kind of active polypeptide; wherein 90% haemolysis peptide exists with unbound state; other 10% then with Melittin N1-formylation form exist (Biochem.Biophys.Res.Commun., 1967,27:275-280).It has very important biologic activity, can cause erythrolysis (Z.Physiol.Chem., 1970,351,884), liposome release mark ion (marker ions) (J.Biol.Chem., 1969,244,3575) and mastocyte discharge histamine (J.Pharmacol, 1965,25,29) or the like.Melittin has two kinds of precursors to exist when synthetic.A kind of is Promelittin, finds at the frog's egg of bee venom or injection queen bee poison gland extract.When synthesizing in frog's egg, Promelittin is stable end product, and in poison gland, it will change Melittin lentamente into; Second kind is called Prepromelittin, and molecular weight ratio Promelittin is big, find on the Melittin mRNA that can only in cell-free system, transcribe (Proc.Natl.Acad.Sct.USA, 1978,75,701-704).

Nineteen eighty-three, Vlasak etc. utilize the total RNA reverse transcription of apis mellifera queen bee poison gland to become cDNA, then the double-stranded cDNA of synthetic is cloned in the pBR322 carrier, the construction cDNA library, filter out to have with probe and insert segmental positive colony greater than 200bp, and then with their subclones in the PUC8 carrier, cut evaluation through enzyme again and therefrom filter out 2 positive colonies, check order to wherein containing the maximum segmental PUM13/4 of insertion, the result shows that this insertion sequence is the nucleotide sequence of Prepromelittin, the mature peptide that this cDNA is coded--melittin precursor protein be 49 amino-acid residues (Eur.J.Biochem., 1983,135:123-126).Prepromelittin albumen comes down to the natural fusion rotein of melittin, and it is synthetic after the dipeptides protease hydrolysis becomes bee venom Melittin in the bee venom cell.

Summary of the invention

One of the object of the invention provides the polynucleotide of a kind of ink chest wasp aptoxin Prepromelittin, the proteic homologue of this polynucleotide encoding apis mellifera bee venom Prepromelittin.Two of the object of the invention provides a kind of final product by ink chest wasp aptoxin Prepromelittin polynucleotide encoding--Asia-africa hornet bee venom Melittin albumen.

The object of the invention also provides this preparation ink chest wasp aptoxin Prepromelittin nucleotide probe, contain the 130-213 nucleotide sequence of ink chest wasp aptoxin Prepromelittin Nucleotide and Prepromelittin gene end (being this a part of nucleotide sequence of Melittin) recombinant vectors, contain the host cell of recombinant vectors and the method for polypeptide antibody.

In the present invention, a kind of isolated dna molecular is provided, it comprises that coding has the nucleotide sequence of the proteic polypeptide of ink chest wasp aptoxin Prepromelittin, show at least 70% homology from the nucleotides sequence of Nucleotide 1-213 position among described nucleotide sequence and the SEQ ID No.5, perhaps described nucleotide sequence can be hybridized from the Nucleotide of Nucleotide 1-213 position under the moderate stringent condition with among the SEQ ID No.5, preferably, this polypeptide has the sequence shown in the SEQ ID No.6.More preferably, this sequence has among the SEQ ID No.5 nucleotide sequence from Nucleotide 1-213 position.

The final expression product of a kind of isolating ink chest wasp aptoxin Prepromelittin--Melittin protein active polypeptide also is provided in the present invention, and it comprises: have polypeptide or its active fragments of SEQ ID No.6 aminoacid sequence, or its reactive derivative.Preferably, this polypeptide is to have SEQ ID No.6 polypeptide of sequence.The present invention also provides a kind of carrier, and it contains above-mentioned isolated DNA; A kind of described carrier transformed host cells.

The present invention also provides a kind of preparation to have the final expression product of ink chest wasp aptoxin Prepromelittin--the method for the proteic active polypeptide of Melittin, and this method comprises:

(a) coding is had the nucleotide sequence of the proteic polypeptide of ink chest wasp aptoxin Prepromelittin and 130～213 nucleotide sequences (being this a part of nucleotide sequence of Melittin) that coding has a Prepromelittin gene end and operationally be connected in expression regulation sequence, form the expression vector of ink chest wasp aptoxin Prepromelittin and Melittin, the nucleotides sequence of described nucleotide sequence and SEQ ID No.5 Nucleotide 1-213 position is shown at least 70% homology;

(b) change the expression vector in the step (a) over to host cell, form the reconstitution cell of ink chest wasp aptoxin Prepromelittin and Melittin;

(c) be fit to express under the condition of ink chest wasp aptoxin Prepromelittin and Melittin the reconstitution cell in the culturing step (b);

(d) isolate polypeptide with ink chest wasp aptoxin Melittin protein-active.

The present invention has found the gene of a kind of ink chest wasp aptoxin Prepromelittin that encodes, the Prepromelittin of this coded by said gene is the natural fusion rotein of bee venom Melittin, bee venom Melittin then is a kind of biologically active peptides, can be applicable to medically painstaking effort official disease, treatment of diseases such as tumour, can be used as antigen and be used for the bee venom immunological reagent, the preparation of bee venom anaphylodiagnosis reagent, can be used as a kind of natural antimicrobial peptide and be used for phytopathy, the control of insect pest also can be used as a kind of model peptide and is used for membrane interaction mechanism, the research of aspects such as the calmodulin mechanism of action.Ink chest wasp aptoxin Prepromelittin gene can be the molecular mechanisms of action relevant with Melittin in the research ink chest wasp aptoxin, for development and use ink chest wasp aptoxin resource provides new foundation.

Embodiment

In a specific embodiments of the present invention, isolating polynucleotide total length of the present invention is 213 Nucleotide, and its detailed sequence is seen SEQ ID No.5, and open reading frame is positioned at 1-213 position Nucleotide.In the present invention, " isolating ", " purifying " or " pure substantially " DNA are meant that this DNA or fragment have been arranged in the sequence of its both sides and have separated under native state; Refer to that also this DNA or fragment with under the native state follow the component of nucleic acid to separate, and separate with the protein of in cell, following it.

In the present invention, refer to encode has the nucleotide sequence of the proteic polypeptide of ink chest wasp aptoxin Prepromelittin to term " ink chest wasp aptoxin Prepromelittin albumen (or polypeptide) encoding sequence ", as 1-213 position nucleotide sequence and degenerate sequence thereof among the SEQ IDNo.5.This degenerate sequence is meant the encoder block 1-213 position Nucleotide that is arranged in SEQ ID No.5 sequence, and having one or more codons to be encoded, the degenerate codon of same amino acid replaces the back and the sequence that produces.Because the degeneracy of codon, thus with SEQ ID No.5 in 1-213 position nucleotide sequence homology be low to moderate about 70%.The degenerate sequence described sequence of SEQ ID No.6 of also encoding out.This term also comprises can be under the moderate stringent condition, more preferably under the height stringent condition, with among the SEQ ID No.5 from the nucleotide sequence of the nucleotide sequence hybridization of Nucleotide 1-213 position.This term also comprise with SEQ ID No.5 in from the homology of nucleotide sequence at least 70% of Nucleotide 1-213 position, preferably at least 80%, at least 90% nucleotide sequence more preferably.

This term also comprises encoding to have variant form with the proteic SEQ ID No.6 sequence of ink chest wasp aptoxin Prepromelittin identical function.These variant forms comprise (but being not limited to): the disappearance of several Nucleotide, insertion and or replace, and add several Nucleotide at 5 ' and/or 3 ' end.

In the present invention, " pure substantially " protein or polypeptide are meant that it accounts at least 20% of the total material of sample, preferably at least 50%, more preferably at least 80%, and at least 90% (by dry weight or weight in wet base) best.Purity can be measured with any suitable method, as measure the purity of polypeptide with post layer folding, PAGE or HPLC method.Substantially pure polypeptide is substantially free of the component of following it under the native state.

In the present invention, term " ink chest wasp aptoxin Prepromelittin protein polypeptide " refers to have the proteic SEQ ID of ink chest wasp aptoxin Prepromelittin No.6 polypeptide of sequence.This term also comprises the variant form that has with the SEQ ID No.6 sequence of ink chest wasp aptoxin Prepromelittin albumen identical function.These variant forms comprise (but being not limited to): several amino acid whose disappearances, insertion and/or replacement, and at C-terminal and/or N-terminal interpolation one or several amino acid.For example, in the art, when replacing, can not change proteinic function usually with the close or similar amino acid of performance.Again such as, add one or several amino acid at C-terminal and/or N-terminal and also can not change proteinic function usually.This term also comprises proteic fragment of ink chest wasp aptoxin Prepromelittin and derivative.

The variant form of this polypeptide comprises: homologous sequence, allelic variant, natural mutation, the induced mutation body, albumen and the final expression product that utilizes anti-ink chest wasp aptoxin Prepromelittin--the polypeptide or the albumen of the antiserum(antisera) acquisition of Melittin polypeptide that can be coded under high or low rigorous degree condition with the DNA of ink chest wasp aptoxin Prepromelittin DNA hybridization.The present invention also provides other polypeptide, as comprises ink chest wasp aptoxin Prepromelittin polypeptide or its segmental fusion rotein.Except the polypeptide of total length almost, the present invention has also comprised the soluble fragments of ink chest wasp aptoxin Prepromelittin polypeptide.Usually, this fragment have ink chest wasp aptoxin Prepromelittin polypeptid coding sequence at least about 10 continuous amino acids, usually at least about 30 continuous amino acids,, be 70 continuous amino acids best preferably at least about 50 continuous amino acids.

Invention also provides the analogue of ink chest wasp aptoxin Prepromelittin albumen or polypeptide, the difference of these analogues and natural ink chest wasp aptoxin Prepromelittin polypeptide can be the difference on the aminoacid sequence, also can be the difference that does not influence on the modified forms of sequence, perhaps have both at the same time.These polypeptide comprise natural or the inductive genetic variant.The induce variation body can obtain by various technology, as by radiation or be exposed to mutagenic compound and produce random mutagenesis, also can pass through site-directed mutagenesis method or the biological technology of other known moleculars.Analogue also comprises having the analogue that is different from the amino acid whose residue of natural L (as D-amino acid), and has non-natural analogue that exist or synthetic amino acid (as β, γ amino acid).Should be understood that polypeptide of the present invention is not limited to the above-mentioned representational polypeptide that exemplifies.

(the not changing primary structure usually) form of modification comprises; The chemically derived form such as the acetylize or carboxylated of the polypeptide that body is interior or external.Modification also comprises glycosylation, carries out glycosylation modified and polypeptide that produce in the procedure of processing as those in the synthetic and processing of polypeptide or further.This modification can be carried out glycosylated enzyme (as mammiferous glycosylation or deglycosylating enzyme) and finishes by polypeptide is exposed to.Modified forms also comprises have the phosphorylated amino acid residue sequence of (as Tyrosine O-phosphate, phosphoserine, phosphothreonine).Thereby also comprise the polypeptide that has been improved its anti-proteolysis performance or optimized solubility property by modifying.

The present invention also comprises ink chest wasp aptoxin Prepromelittin polypeptid coding sequence and segmental antisense sequences thereof, and this antisense sequences can be used for suppressing the expression of ink chest wasp aptoxin Prepromelittin in the cell.

The present invention also comprises a kind of probe molecule, and this molecule has 8-100 of ink chest wasp aptoxin Prepromelittin polypeptid coding sequence, preferably 1-50 continuous nucleotide usually.This probe can be used for whether existing in the test sample coding ink chest wasp aptoxin Prepromelittin nucleic acid molecule.

The present invention also comprises the method that detects ink chest wasp aptoxin Prepromelittin nucleotide sequence, it comprises with above-mentioned probe and sample and hybridizing, whether detection probes combination has taken place then, preferably, this sample is the product behind the pcr amplification, wherein the pcr amplification primer is corresponding to the encoding sequence of ink chest wasp aptoxin Prepromelittin polypeptide, and can be positioned at the both sides or the centre of this encoding sequence, and primer length is generally 15-50 Nucleotide.

In the present invention, can select various carrier known in the art for use, as commercially available carrier.

In the present invention, term " host cell " comprises prokaryotic cell prokaryocyte and eukaryotic cell.The example of prokaryotic host cell commonly used comprises intestinal bacteria, Bacillus subtilus etc.Eukaryotic host cell commonly used comprises yeast cell, insect cell and mammalian cell, and preferably, this host cell is an eukaryotic cell, as Tn cell, Chinese hamster ovary celI, COS cell etc.

On the other hand, the present invention also comprises ink chest wasp aptoxin Prepromelittin or the polypeptide of its fragment coding has specific polyclonal antibody and monoclonal antibody, especially monoclonal antibody.Here, " specificity " is meant that antibody capable is incorporated into ink chest wasp aptoxin Prepromelittin gene product or fragment.Preferably, refer to that those can combine with ink chest wasp aptoxin Prepromelittin gene product or fragment but nonrecognition and be incorporated into the antibody of other irrelevant antigen molecule.Among the present invention antibody comprise those can in conjunction with and suppress final expression product--the proteic molecule of Melittin of ink chest wasp aptoxin Prepromelittin gene, comprise that also those do not influence the final expression product of ink chest wasp aptoxin Prepromelittin gene--the antibody of Melittin protein function.The present invention also comprise those can with modify or without final expression product--the Melittin bonded antibody of the ink chest wasp aptoxin Prepromelittin gene of modified forms.

The present invention not only comprises complete mono-clonal or polyclonal antibody, but also comprises having immunocompetent antibody fragment, as Fab ' or (Fab) ₂Fragment; Heavy chain of antibody; Light chain of antibody; Genetically engineered strand Fv molecule (people such as Ladner, U.S. Patent No. 4,946,778); Or chimeric antibody, as have the murine antibody binding specificity but still keep antibody from the antibody moiety of Asia-africa hornet.

Antibody of the present invention can be prepared by the known various technology of those skilled in that art, for example, the ink chest wasp aptoxin Prepromelittin gene product of purifying or its have antigenic fragment, can be applied to animal to induce the generation of polyclonal antibody.Similarly, expressing ink chest wasp aptoxin Prepromelittin or its has antigenic segmental cell and can be used to immune animal and prepare antibody.Antibody of the present invention also can be monoclonal antibody.This type of monoclonal antibody can utilize hybridoma technology to prepare that (see people such as Kohler, Nature 256; 495,1975; People such as Kohler, Eur.J.Immunol, 6:511,1976; People such as Kohler, Eur.J.Immunol, 6:292,1976; People such as Hammerling, In MonoclonalAntibodies and T Cell Hybridomas, Elsevier, N.Y., 1981).Antibody of the present invention comprises the final expression product that can block ink chest wasp aptoxin Prepromelittin gene--the antibody of Melittin function and the antibody that does not influence ink chest wasp aptoxin Melittin function.Each antibody-like of the present invention can utilize the fragment or the functional zone of ink chest wasp aptoxin Prepromelittin gene product, obtains by the routine immunization technology.These fragments or functional zone can utilize recombinant methods or utilize Peptide synthesizer synthetic.Can come immune animal and produce with the gene product of preparation in the prokaryotic cell prokaryocyte (for example E.coli) with the final product unmodified form bonded antibody of ink chest wasp aptoxin Prepromelittin gene; With posttranslational modification form bonded antibody (as the albumen or the polypeptide of glycosylation or phosphorylation), can come immune animal and obtain with the gene product that produces in the eukaryotic cell (for example yeast or insect cell).

In one embodiment of the invention, the cDNA nucleotide sequence of ink chest wasp aptoxin Prepromelittin is so to obtain, cDNA with the total RNA reverse transcription of ink chest wasp poison gland is a template, with a pair of oligonucleotide is that primer-A:5 '-GCTCGAGATGAAATTCTTAGTCAACGTT-3 ' is that forward is to primer, oligonucleotide B:5 '-GAAGCTTCTAACCCTGTTGCCTCTT-3 ' is a reverse primer, carries out PCR.Obtain the cDNA sequence of SEQ ID No.5 after amplified production checked order.Ink chest wasp aptoxin Melittin is the final albumen of Prepromelittin genetic expression in the ink chest wasp poison gland, and ink chest wasp aptoxin Prepromelittin of the present invention provides the foundation for the molecular mechanisms of action relevant with Melittin in the research ink chest wasp aptoxin.

Below in conjunction with specific examples, further set forth the present invention.Should be understood that these embodiment only to be used to the present invention is described and be not used in the restriction scope of the invention.

Embodiment 1, the clone of the cDNA of ink chest wasp aptoxin Prepromelittin and mensuration

1. primer amplification

CDNA with the total RNA reverse transcription of ink chest wasp poison gland is a template, with a pair of oligonucleotide is that primer-A:5 '-GCTCGAGATGAAATTCTTAGTCAACGTT-3 ' (SEQ ID No.1) is that forward is to primer, oligonucleotide B:5 '-GAAGCTTCTAACCCTGTTGCCTCTT-3 ' (SEQID No.2) is a reverse primer, carries out PCR.The PCR condition of A/B be 94 ℃ 3 minutes, thereupon with 94 ℃ of 40 second, 54 ℃ of 40 second and 72 ℃ carried out 35 circulations in 1 minute, last 72 ℃ were extended 10 minutes, electrophoresis detection obtains the purpose fragment of about 220bp.

2.PCR the order-checking of product

With above-mentioned pcr amplification product A/B and PGEM ^-T carrier (Promega) connects, transformed into escherichia coli JM109, extract plasmid with alkaline process, with BigDye terminator v2.0 (Applied BiosystemIncorporation) sequencing kit extractive plasmid is checked order, with computer software splicing order, obtain the cDNA sequence at last, altogether 213bp, detailed sequence is seen SEQ ID No.5, and wherein open reading frame is positioned at 1-213 position Nucleotide.

Derive the aminoacid sequence of ink chest wasp aptoxin Prepromelittin according to the cDNA sequence that obtains, totally 70 amino-acid residues, its aminoacid sequence sees SEQ ID No.6 for details.

Embodiment 2, and homology relatively

CDNA sequence and proteins encoded thereof with ink chest wasp aptoxin Prepromelittin of the present invention, in Non-redundant GenBank+EMBL+DDBJ+PDB database and Non-redundant GenBankCDS translations+PDB+SwissProt+Spupdate+PIR database, carry out nucleic acid and albumen homology retrieval with the Blast program.Found that it and apis mellifera bee venom Prepromelittin have significant homology.With the GENTYX software analysis as can be seen, their proteic homology is 95% (seeing attached list 1).Therefore, can infer that ink chest wasp aptoxin Prepromelittin albumen of the present invention is the homologue of apis mellifera bee venom Prepromelittin, and have similar function.

Nineteen eighty-three, people's Applied Biotechnology methods such as Vlask, utilize the total RNA reverse transcription of apis mellifera queen bee poison gland to become cDNA, by the construction cDNA library, do the library screening with probe then, obtained the new gene of coding apis mellifera bee venom Prepromelittin, the signal peptide of the Prepromelittin that this cDNA is coded and mature peptide are 70 amino-acid residues, 21 amino-acid residues that wherein begin are signal peptide, remaining 49 is mature peptide, comprises the aminoacid sequence (44～70) of terminal M elittin.The aminoacid sequence of ink chest wasp aptoxin Prepromelittin coded by said gene contains above-described corresponding signal peptide and mature peptide among the present invention, comprises the aminoacid sequence (44～70) of terminal Melittin.Prepromelittin last expression product in ink chest wasp is Melittin.And Melittin is present medical science, the very useful active polypeptide of agricultural and biology aspect, it can influence the signal transducting system of cell by multipath, and can induce the synthetic and natural death of cerebral cells of ceramide, have anti-inflammatory, various biological effect such as antibiotic, antiviral; Simultaneously, Melittin has also become a kind of model peptide, is widely used in the research of aspects such as membrane interaction mechanism, the calmodulin mechanism of action.The inventor's ink chest wasp Prepromelittin gene is the molecular mechanisms of action relevant with Melittin in the research ink chest wasp aptoxin, for development and use ink chest wasp aptoxin resource provides new foundation.

Embodiment 3, the amalgamation and expression of 130～213 nucleotide sequences of ink chest wasp aptoxin Prepromelittin gene end (being this a part of nucleotide sequence of Melittin) in intestinal bacteria

In this embodiment, with pcr amplification product among the embodiment 1 as inserting fragment.

5 ' the Oligonucleolide primers sequence of using in the PCR reaction is:

5 '-CGTGGATCCGGAATTGGAGCAGTTCTG-3 ' (SEQ ID No.3), this primer contains the restriction enzyme site of BamH I restriction enzyme, is 21 Nucleotide of ink chest wasp aptoxin coding Melittin sequence after this restriction enzyme site;

3 ' end primer sequence is:

5 '-CGGGAATTCCTAACCCTGTTGCCTCTT-3 ' (SEQ ID No.4), this primer contains the restriction enzyme site of EcoR I restriction enzyme, the partial nucleotide sequence of translation termination and coding Asia-africa hornet bee venom Melittin.

The restriction enzyme site of the restriction enzyme on the primer is corresponding to the restriction enzyme site of the restriction enzyme on the bacterial expression vector pGEX-4T-3, this plasmid vector coding antibiotics resistance (Amp ^r), a bacterium replication orgin (Ori), an adjustable promotor/operon of IPTG (P/O), a ribosome bind site (RBS), a gsh marker (GST) and restriction enzyme cloning site.

With BamH I and EcoR I digestion pGEX-4T-3 carrier and insertion fragment, will insert fragment subsequently and be connected to the pGEX-4T-3 carrier and keep open reading frame initial at bacterium RBS.With connecting the E.coli bacterial strain that mixture transforms commodity BL21 by name, BL21 contains the recombinant plasmid of multiple copied subsequently, and it is expressed lac I repressor and carries ammonia benzyl resistance (Amp ^r), containing Amp ^rThe LB culture dish on screen transformant, the extracting plasmid, in the sequence verification ink chest wasp aptoxin coding Melittin the cDNA fragment correctly inserted carrier.Adding Amp ^rIncubated overnight (O/N) contains the positive transformant clone of required construction in the LB liquid nutrient medium of (100 μ g/ml).(O/N) culture that spends the night dilutes with 1: 10 thinning ratio, is inoculated into then in the large volume LB liquid nutrient medium, and culturing cell grows to 600 optical density(OD) (OD ₆₀₀) when being 0.4-0.6, add IPTG (" isopropyl-β-D-thiogalactoside ") to final concentration be 1.0mM.By making lacI repressor inactivation, IPTG induces startup P/O to cause gene expression dose to improve.Continue culturing cell after 3-5 hour, centrifugation cell, and with the PBS of 1/20 volume it is suspended; Supersound process lysing cell subsequently; Add Triton X-100 down to final concentration 1% in room temperature (25 ℃) again, mixed gently 30 minutes; Subsequently 10, centrifugal 5 minutes of 000g collects supernatant, the fusion rotein of having expressed with GST Purification Modules purifying again.At last, protein is kept in the stock solution that final concentration is 10% (w/v) glycerine.

SDS-PAGE glue with 15% carries out electrophoresis, identifies that the molecular weight size of expressing protein is about 29.0KDa.

In addition, the amino acid of expressing proteic N end and each 10 amino acid length of C end is checked order, find consistent with the sequence of SEQ ID No.6 with ordinary method.

Embodiment 4, the expression of ink chest wasp aptoxin Prepromelittin in eukaryotic cell (Tn cell strain, i.e. cabbage looper cell strain)

In this embodiment, with pcr amplification product among the embodiment 1 as inserting fragment.

5 ' the Oligonucleolide primers sequence of using in the PCR reaction is:

5 '-GCTCGAGATGAAATTCTTAGTCAACGTT-3 ' (SEQ ID No.1), this primer contains the restriction enzyme site of Xho I restriction enzyme, is 21 Nucleotide of the ink chest wasp aptoxin Prepromelittin encoding sequence that begins of signal peptide after this restriction enzyme site;

3 ' end primer sequence is:

5 '-GAAGCTTCTAACCCTGTTGCCTCTT-3 ' (SEQ ID No.2), this primer contains the restriction enzyme site of Hind III restriction enzyme, the part encoding sequence of translation termination and ink chest wasp aptoxin Prepromelittin.

Restriction enzyme digestion sites is corresponding to the restriction enzyme digestion sites on the Tn fibrocyte expression vector pBacFastHTb on the primer, this plasmid vector coding antibiotics resistance (Amp ^rAnd Gm ^r), a phage replication starting point (Ori), a virus replication starting point (SV40), T7 promotor, a viral promotors (P-CMV), a SV40 promotor, a SV40 tailing signal and corresponding polyA order, a BGH tailing signal and corresponding polyA order.

With Xho I and Hind III digestion pBacFastHTb carrier and insertion fragment, with linking mixture Transformed E .coli TG I bacterial strain, containing Amp subsequently ^rAnd Gm ^rThe LB culture dish on screen transformant, add Amp ^rAnd Gm ^rThe LB liquid nutrient medium in cultivate the clone that (O/N) contains required construction, the extracting plasmid, the cDNA fragment of sequence verification ink chest wasp aptoxin Prepromelittin has correctly been inserted carrier.Use recombinant plasmid transformed E.coli DH10Bac bacterial strain subsequently, containing Kan ^r, Gm ^r, tsiklomitsin the LB culture dish on screen transformant, adding Kan ^r, Gm ^r, tsiklomitsin the LB liquid nutrient medium in cultivate the clone that (O/N) contains required construction, the extracting plasmid through Sepharose 2B column purification, reclaims plasmid-70 ℃ preservation.

Plasmid transfection Tn cell is to adopt lipofection, carries out with Lipofectin (GiBco Life).After the transfection 48 hours, collecting cell and cell conditioned medium, the cell conditioned medium that contains the recombinant virus particle is used for next round to be infected.Cultivate through the TC-100 in 2-3 week continuous passage, collecting cell with ultrasonic degradation method smudge cells, is balance liquid and elutriant with 20mM Tris-CI (PH8.0) solution that contains NaCl0.5mM, imidazola 5mM, PMSF 1mM, the Ni of protein liquid through pre-equilibration ²⁺Sepharose 6B post is crossed post; Use the solution of the 20mM Tris-CI (PH8.0) that contains imdazola50mM, NaCl 0.5mM, PMSF 1mM again, the flush away foreign protein, the fusion rotein of 6 * His of narrow spectrum absorption, the solution with the 20mM Tris-CI (PH8.0) that contains imdazola 500mM, NaCl 0.5mM, PMSF 1mM carries out wash-out again.Be that dialyzate is dialysed to expressing protein solution with PBS (PH7.4) then.Last freeze-drying is preserved.

With the 16%T that contains 6mol/L urea element (or 24% glycerine), 6%C and 8%T, the 2L-T-SDS-PAGE of 3%C carries out electrophoresis, identifies that the molecular weight size of expressing protein is about 3.0KDa.

In addition, with ordinary method the amino acid of expressing proteic N end and each 10 amino acid length of C end is checked order the albumen of discovery and the white ID No.6 of SEQ, sequence unanimity.

Embodiment 5, preparation antibody

The recombinant protein that obtains in embodiment 3 and 4 is used for immune animal to produce antibody; And concrete grammar is as follows.Recombinant molecule is standby after separating with affinity chromatography.Also available SDS-PAGE gel electrophoresis separates; And electrophoretic band is downcut from gel. also with isopyknic complete Freund ' s adjuvant emulsion.With the albumen of g/ emulsification of 200-300 μ; To the rabbit subcutaneous injection in 12 ages in week.After 21 days; carry out subcutaneous multiple spot and leg muscle injection with booster immunization with the dosage of 100-200 μ g/ head with the same antigen of non-complete Freund ' s adjuvant emulsion.Carry out one time the intragluteal injection booster immunization after 21 days again.The ability that sero-fast specific reaction activity precipitates ink chest wasp aptoxin Prepromelittin gene translation product in vivo with it is assessed.The explanation of SEQ ID No.1 ∽ 6, information ( i ) the sequence signature CA of SEQ ID NO.1 ) length:type 28 base CB ) : nucleic acid ( C ) chain:strand ( D ) topology; Linearity is molecule-type (ii): (vi) sequence description:information (i) sequence signature (A) length of SEQ ID NO.1GCTCGAGATGAAATTCTTAGTCAACGTTSEQ ID NO.2:25 bases (B) type:nucleic acid (C) chain:strand (D) topology:linearity is molecule-type (ii): oligonucleotide (vi) sequence description for oligonucleotide; The information of SEQ ID NO.2GAAGCTTCTAACCCTGTTGCCTCTTSEQ ID NO.3:(i) sequence signature (A) length:27 bases (B) type:nucleic acid (C) chain:strand (D) topology:linearity is molecule-type (ii): oligonucleotide (vi) sequence description; The information of SEQ ID NO.3CGTGGATCCGGAATTGGAGCAGTTCTGSEQ ID NO.4:(i) sequence signature (A) length:27 bases (B) type:nucleic acid (C) chain:strand (D) topology:linearity is molecule-type (ii): oligonucleotide (vi) sequence description; The information of SEQ ID NO.4CGGGAATTCCTAACCCTGTTGCCTCTTSEQ ID NO.5:(i) sequence signature (A) length:213bp (B) type:nucleic acid (C) chain:strand (D) topology; Linear (ii) molecule-type:cDNA (vii) is sequence description (vi): the information of SEQ ID NO.51 ATGAAATTCT TAGTCAACGT TGCCCTTGTT TTTATGGTTG TATACATTTC TTTCATCTAT61 GCGGCCCCTG AACCAGAACC GGCACCGGAG GCAGAGGCAG AGGCAGACGC GGAGGCAGAT121 CCGGAAGCAG GAATTGGAGC AGTTCTCAAA GTATTAACCA CAGGATTGCC TGCCCTTATA181 AGTTGGATTA AACGTAAGAG GCAACAGGGT TAGSEQ ID NO.6:(i) sequence signature (A) length:70 amino acid (B) type:amino acid (C) topological structure; ( ii ) ： ( vi ) ：SEQ ID NO.61 Met Lys Phe Leu Val Asn Val Ala Leu Val Phe Met Val Val Tyr Ile Ser Phe Ile Tyr21 Ala Ala Pro Glu Pro Glu Pro Ala Pro Glu Ala Glu Ala Glu Ala Asp Ala Glu Ala Asp41 Pro Glu Ala Gly Ile Gly Ala Val Leu Lys Val Leu Thr Thr Gly Leu Pro Ala Leu Ile61 Ser Trp Ile Lys Arg Lys Arg Gln Gln GlyI PrepromelittinPrepromelittin：VvPrepromelittin：70AmPrepromelittin：70“*”AmPrepromelittin1：MKFLVNVALVFMVVYISYIYAAPEPEPAPEPEAEADAEADPEAGIGAVLKVLTTGLPALI60VvPrepromelittin1：MKFLVNVALVFMVVYISFIYAAPEPEPAPEAEAEADAEADPEAGIGAVLKVLTTGLPALI60

****************?*************?*****************************AmPrepromelittin61：SWIKRKRQQG 70VvPrepromelittin61：SWIKRKRQQG 70

* * * * * * * * * homology: 97%

Claims (10)

1. An isolated DNA molecule, characterized in that it comprises: a nucleotide sequence encoding a precursor polypeptide of Vespa venom hemolytic peptide; The nucleotide sequence has at least 70% homology to the nucleotide sequence from nucleotide 1-213 in SEQ ID No.5; or the nucleotide sequence can be obtained under moderately stringent conditions Hybridization with the nucleotide sequence from nucleotides 1-213 in SEQ ID No.5. 2. according to the DNA molecule of claim 1 SEQ ID No.5, it is characterized in that, the polypeptide of described coding has the sequence shown in SEQ ID No.6, has from nucleotide 1-213 in SEQ ID No.5 the nucleotide sequence. 3. A final expression product of the isolated Vespa venom hemolytic peptide precursor gene-hemolytic peptide protein polypeptide, characterized in that it has a polypeptide of SEQ ID No.6 amino acid sequence, or an active fragment thereof, or Active derivatives, the polypeptide has the sequence of SEQ ID No.6. 4. A vector comprising the DNA according to claim 1. 5. A host cell, characterized in that it is a host cell transformed with the vector according to claim 4. 6. A method for preparing the final expression product of the hemolytic peptide precursor gene of the Vespa venom, the hemolytic peptide protein polypeptide, characterized in that the method comprises: (a) operably linking the nucleotide sequence encoding the hemolytic peptide precursor polypeptide with the vespa venom and the 130-213 nucleotide sequence at the end of the hemolytic peptide precursor gene to the expression control sequence to form the vespa wasp The expression vector of the toxin hemolytic peptide precursor and the hemolytic peptide, the nucleotide sequence has at least 70% homology with the nucleotide sequence from nucleotide 1-213 in SEQ ID No.5; (b) transferring the vector expressed in step (a) into a host cell to form recombinant cells of Vespa venom hemolytic peptide precursor and hemolytic peptide; (c) culturing the recombinant cells in step (b) under conditions suitable for expressing the hemolytic peptide precursor and the hemolytic peptide of Vespa japonica; (d) isolating the polypeptide having the activity of the Vespa venom hemolytic peptide protein. 7. An antibody, characterized in that it is an antibody capable of specifically binding to the final expression product of the Vespa venom hemolytic peptide precursor gene-hemolytic peptide protein active polypeptide according to claim 3. 8. A probe molecule, characterized in that it contains 8-100 consecutive nucleotides in the DNA molecule according to claim 1. 9. The probe molecule according to claim 8; characterized in that it refers to an antibody that can bind to the gene product or fragment of the Vespa venom hemolytic peptide precursor but does not recognize and bind to other irrelevant antigen molecules. 10. The probe molecule according to claim 8, characterized in that it has 15-20 consecutive nucleotides in the coding sequence of the Vespa venom hemolytic peptide precursor polypeptide.