Characterization and immunofluorescence localization analysis of carboxypeptidase A in molt fluid of silkworm / 生物工程学报

Molting is an important physiological phenomenon of many metamorphosis insects, during which the old and new epidermis are separated by enzymes present in the molting fluid. Various proteomic studies have discovered the presence of Bombyx mori carboxypeptidase A (Bm-CPA) in the molting fluid of silkworm, but its function remains unclear. In order to better understand the role of Bm-CPA in the molting process of silkworm, Bm-CPA was analyzed by bioinformatics analysis, real-time fluorescence quantitative PCR, antibody preparation, immunofluorescence staining, and expression in Pichia pastoris. The results showed that Bm-CPA had a conserved M14 zinc carboxypeptidase domain and glycosylation site. Its expression was regulated by ecdysone 20E, and large expression was observed in the epidermis of the upper cluster stage. Immunofluorescence staining showed that Bm-CPA was enriched in the epidermis during the molting stage, and the inhibitor of Bm-CPA led to the larval death due to the inability to molt. We also successfully obtained a large number of recombinant Bm-CPA proteins by Pichia pastoris expression in vitro. These results may facilitate further understanding the molting development process of silkworm.

Study on expression and activity of combinant antimicrobial peptide in Pichia pastoris / 国际检验医学杂志

Objective To construct cecropin A-thanatin combinant gene engineering antimicrobial peptide gene CA(1-7)-T(4-19) for expression in Pichia pastoris.Methods The combinant antimicrobial peptide gene was artificially synthesized via gene splicing by overlap extension (SOE).The gene was cloned into the pPICZαA vector and transformed into Pichia pastoris X-33 by electroporation.The positive clones obtained by the screening of bleomycin resistance were induced by methanol ,and the antibacterial activity of the products was detected and the antimicrobial spectrum was established.Results The combinant peptide gene CA (1-7)-T (4-19) was successfully cloned on the carrier pPICZαA.The identification results were consistent with the pre-designed gene sequence.The combinant peptide gene was expressed under the induction of methanol ,and the minimum inhibitory concentration of 76 strains of Gram-egative and Gram-positive pathogenic bacteria isolated from the clinic was obtained ,and the minimum inhibitory concentration was up to 5 μg/mL.Conclusion A combinant genetic engineering antimicrobial peptide with antibacterial activity was obtained successfully and it had obvious inhibition effect on clinical common multidrug-resistant strains.

Construction and identification of Stathmin gene Pichia pastoris expression system / 国际检验医学杂志

Objective To provide the experimental basis for the further research of the interacting proteins with Stathmin ,the Stathmin gene Pichia pastoris expression system was constructed ,the expressed Stathmin product was purified and identified .Meth‐ods Stathmin gene was amplified from tumor cell line of SKBR3 by PCR method and cloned into the yeast expression vector pPIC3 .5K .The recombinant vector pPIC3 .5K‐Stathmin was constructed and transformed into Pichia pastoris GS115 .The positive clones were screened by YPD medium containing Geneticin 600 μg/mL .Expression was induced with 0 .5% methanol and expres‐sion products were identified by SDS‐PAGE and Western Blotting .Results DNA sequencing result showed that the gene fragment was consistent with Stathmin gene sequence .pPIC3 .5K‐Stathmin was selected from YPD culture medium containing Geneticin ,and the positive clones were identified by PCR .SDS‐PAGE showed that a 37 × 103 protein band could be seen on the PAGE gel after Coomassie Blue staining ,which was further confirmed and identified as Stathmin protein by Western Blotting .Conclusion Stathmin yeast expression vector is successfully constructed and expressed in Pichia pastoris ,which laid the foundation for the study of inter‐acting proteins with Stathmin ,and for the preparation of the biological treatment drugs of Stahtmin target .

Clonagem, expressão e caracterização de um inibidor de agregação plaquetária proveniente dos complexos salivares de sanguessugas Haementeria depressa / Cloning, expression and characterization of a platelet aggregation inhibitor from Haementeria depressa leech salivary complexes

Animais hematófagos possuem em sua saliva substâncias que permitem a fluidez do sangue, para o sucesso de sua alimentação. Com isso, têm sido descritos diversos componentes com atividades nos diferentes processos hemostáticos (coagulação, fibrinólise e agregação plaquetária). O complexo salivar da sanguessuga Haementeria depressa vem sendo estudado através de bioquímica clássica e análises transcriptômica e proteômica deste tecido determinaram o perfil dos transcritos e das proteínas produzidas. Dentre os transcritos mais abundantes foram encontrados três clones (H06A09, H06A02 e L02F02) que apresentaram 45%, 87% e 94% de similaridade ao LAPP, um inibidor de agregação plaquetária da sanguessuga Haementeria officinallis, a produção destes componentes pelo tecido foi confirmada pela análise proteômica. O LAPP é um inibidor que age pela via do colágeno e possui cerca de 14 kDa e pI de 4,0 e inibe a ligação da plaqueta ao colágeno tanto pelo epítopo do FvW quanto pelo domínio a2b1. Assim, o objetivo do presente trabalho foi clonar, expressar e caracterizar a proteína recombinante ativa, a partir do clone H06A09 para estudos de atividade desta molécula. Para obter a proteína recombinante de interesse inicialmente a clonagem do transcrito foi realizada com sucesso em vetor pAE, porém, a expressão em sistema procarioto apresentou alguns obstáculos já que a molécula não tinha atividade. Uma nova estratégia foi proposta, sendo realizada clonagem em vetor pPIC9K e expressão em sistema eucariótico (leveduras Pichia pastoris - GS115). Desta forma, o presente trabalho caracteriza o primeiro inibidor recombinante de agregação plaquetária pela via do colágeno proveniente de sanguessugas Haementeria depressa, e comprova que apesar de apresentar 45% de similaridade estrutural ao LAPP é um inibidor com características funcionais diferentes, e com grande potencial a ser estudado.

Hematophagous animals have in their saliva substances that maintain the blood fluidity to the success of their feeding. Therefore, components have been described by their activities in the hemostatic processes (coagulation, fibrinolysis and platelet aggregation).The salivary complex of Haementaria depressa leech has been studied by classical biochemical and transcriptomic and proteomic analysis of this tissue determined the profile of transcripts and proteins produced by it. Among the most abundant transcripts were found three clones (H06A09, H06A02 e L02F02) that showed 45%, 87% e 94% of similarity to LAPP, an inhibitor of platelet aggregation from Haementeria officinallis, the components production was confirmed by proteomic analysis. LAPP is a inhibitor that acts by collagen pathway and has around 14 kDa and pI of 4.0, and inhibits the binding of platelet to collagen by both the epitope domain of vWF as the a2b1. Thereby, the aim of this study was to clone, express and characterize the active recombinant protein from the clone H06A09 for studies of activity of this molecule. To obtain the recombinant protein initially cloning of transcript was successfully performed in pAE vector, however, the protein expressed in prokaryotic system presented some obstacles not presenting activity. A new strategy was proposed, being held in pPIC9K vector and expression in eukaryotic system - yeast Pichia pastoris (GS115). Thus, this study characterized the first recombinant inhibitor of platelet aggregation through collagen pathway from Haementeria depressa leeches, and proves that despite having 45% structural similarity to the LAPP is an inhibitor with different functional characteristics, and great potential to be studied.

Expression and Bioactivity Assay of a Novel Clamworm Antimicrobial Peptide Perinerin in Pichia pastoris / 中国生物工程杂志

A novel antimicrobial peptide, named as perinerin (GenBank accession No. P84117), was isolated and characterized from Asian marine clamworms, Perinereis aibuhitensis Grube. Perinerin showes powerful and broad activity against both grampositive and gramnegtive bacteria in vitro, especially on Pseudemonas aeruginosa. To obtain large amounts of active perinerin and characterize its main physiochemical features, The perinerin weve expressed in Pichia pastoris. Intact perinerin gene amplified by the modified gene SOEing method(Gene splicing by overlap extension)was cloned into expression vector pPICZ?A and obtained recombinant vector pPICZ?APEN, then pPICZ?APEN was expressed in the Pichia pastoris GS115. The expressed sample was analyzed by TricineSDSPAGE. The results showed that Pichia pastoris was a suitable system producing the secreted form of perinerin. Bioactivity assay showed that the recombinant perinerin had marked antimicrobial effects.

Secreted Expression of M annanase Gene in Pichia pastoris and Anylysis of Enzymic Properties / 中国生物工程杂志

A PCR method was used to amplify the sequence encoding the mature peptide of?-mannanase of Bacillus subtilis. The gene was inserted into the Pichia pastoris vector pPIC9K, downstream of?-factor signal peptide sequence. The resultant recombinant plasmid pPIC9K-MAN was lineared by BglII digestion and introduced into the host Pichia pastoris GS115 by PEG method. After screen, the recombinant P. pastoris strain MAN22 was obtained and fermented in large scale 5L fermenter. The recombinant mannanase activity could reach to 1102IU/ml. The properties of the recombinant mannanase were characterized.

Cloning of survivin-an inhibitor of apoptosis proteins and expressed in pichia pastoris system / 肿瘤研究与临床

Objective To clone human survivin gene and express survivin-an inhibitor of apoptosis proteins in Pichia pastoris eukaryotic expression system. Methods Full length survivin gene was amplified by PCR using survivin specific primers. The verified survivin gene by sequencing was subcloned into pPic9k. The recombinant plasmid was linearized by restriction enzyme cutting. The linear survivin gene was introduced into GS115/ His-cells by electroporation. The transformants were transferred onto YPD plates that contained different concentrations of G418 for screening the positive clones. The integrated survivin gene in positive clones was confirmed by PCR. Selected transformants were cultured in BMMY medium with 1 % methanol for inducing the expression of survivin protein. The expressed survivin protein was analyzed by ELISA. Results The cloned human survivin sequence was the same as that in the GeneBank. The recombinant pPic9k-survivin was constructed in Picha pastoris eukaryotic expression vector. After the linear digestion, the recombinant vector was introduced into GS115/ His-cells, the 6 positive clones against G418(4 mg/mL) were obtained and confirmed by PCR; the highest survivin protein was expressed when expressed for two days in 1 % methanol BMMY medium. Conclusions Improved survivin protein yield may be reached by modifying the experimental conditions. This will help to further study the biological functions of survivin and its roles in tumor developments.

High Expression of mdlA Gene in Pichia pastoris and Study of Properties of the Recombinant Lipase / 微生物学通报

The mono-and diacylglycerol lipase(MDGL)-encoding gene(mdlA) was inserted into methanol-inducible expression vector pPIC9K.The linearized recombinant plasmid was uransformed into chromosome of Pichia pastoris GS115 strain by electroporation.Some high-copy transformants(His~(+)Mut~(+)) were picked up by G-418 and conformed by PCR.SDS-PAGE analysis indicated efficient expression of recombinant MDGL.Some enzymatic properties of the recombinant MDGL were also determined.The activity of the recombinant MDGL was up to 325U/mL under the optimal conditions and no activity was detected towards olive oil.The amount of fatty acid produced by the catalysis of recombinant MDGL and triacylglycerol lipase had a increase of 93.5% over triacylglycerol lipase lonely.

Expression of VP2 Gene of Feline Panleukopenia Virus Isolated from Tiger in Pichia pastoris Yeast / 微生物学通报

In this study,the VP2 gene of feline panleukopenia virus(FPV) isolated from tiger was successfully cloned and expressed in Pichia pastoris yeast.The VP2 gene was amplified by PCR with a pair of specific primer.Then PCR products was purified and cloned into pGEM-T for sequencing.The interesting gene fragment was recovered after the double enzyme digestion of EcoRI/NotI,then subcloned into pPICZ?A for secretory expression.The recombinant pPICZ?AVP2 was linearized with SacI and then transformed into competence yeast GS115 for expression under the induction of 1% methanol.The positive recombinants were screened by PCR method.The expression product was identified by SDS-PAGE and western-blotting.The results showed that there was a molecular weight of 32 kD,which could be specifically recognized by polyclonic antibody against FPV.It revealed that the recombinant VP2 protein had correct three-dimensional structure,which would be used as a antigen protein for the diagnosis and prevention of FPV infection in tigers.

Cloning of Endoglucanase I Gene from Trichoderma longi-brachiatum and Its Expression in Pichia pastoris / 微生物学通报

A cellulase high-yield strain was identified and named as Trichoderma longibrachiatum SSL by ITS sequence identification. The endoglucanase1 gene (eg1) encoding endo-l,4-?-D-glucanase I was ampli-fied by RT-PCR method, which including 1386 bp and encoding 461 amino acid. Sequence analysis showed that: This gene has a more 90% homology with the T. longibrachiatum eg1 gene. The eg1 gene encoding the mature peptide was inserted into the Pichia pastoris expression vector pPIC9K, which resulted in construc-tion of the recombinant expression plasmid, pPIC9k-eg1. The pPIC9k-eg1 was then introduced into the host Pichia pastoris GS115. After the induction of methanol, extracellular recombinant endoglucanase I from the supernatant of the recombinant Pichia pastoris strain reached 73 U/mL. A clear strengthening of the protein bands, whose molecular weight is about 58 kD, appeared in the SDS-PAGE.

Cloning of Acidic Xylanase Gene and Its Secretion Expression in Pichia pastoris / 微生物学通报

An acidic xylanase gene,named xyl3,was cloned from the genomic library of enviromental microbes constructed by using shotgun cloning strategy,and submitted to GeneBank with accession number of gb:AY300805.BLAST analysis indicated that the gene xyl3 has low similarity with other xylanase genes and the encoded xylanase,sorted as Glycosyl hydrolases family 10,has 77% similarity with the intra-cellular xylanase from Geobacillus stearothermophilus at amino acid level.Treated with T4 DNA polymerase,the gene xyl3 was ligated with the linearized Pichia pastoris expression vector pHBM905 produced by digestion of restriction endonuclease CpoI and NotI to generate the recombinant plasmid pHBM706.Then the plasmid pHBM706,digested by restriction endonuclease SalI,was transformed into P.pastoris GS115 to obtain the recombinant P.pastoris GS115(pHBM706),which was induced to produce the recombinant xylanase with 0.5% methanol at 28℃.At the 36th hours of induction,the porduced crude enzyme was detected to reach the higest enzyme activity of 0.177 IU/mL.The optimal pH and temperature of the enzyme activity is 5.5 and 50℃ respectively.