Expression,purification and identification of fully human monomolecular antibody against Clostridium perfringens type A α-toxin / 中国生物制品学杂志

@#Objective To express,purify and identify human monomolecular antibody against Clostridium perfringens type A α-toxin,in order to lay a foundation for the prevention and treatment of various diseases caused by this toxin.Methods The fully human single-chain fragment variable(ScFv) gene against Clostridium perfringens type A was linked with the constant region of light chain and heavy chain of human antibody in different combinations to construct multiple monomolecular antibody expression plasmids against Clostridium perfringens α-toxin,which were expressed in competent E.coLi BL21(DE3).Indirect ELISA was used to detect the immunobinding activity of the monomolecular antibodies,and the monomolecular antibody with the highest immunobinding activity was purified by SepharoSe 4 FF and rProtein-A FF affinity chromatography,The purified products were analyzed by 12% SDS-PAGE.Indirect ELISA was used to detect the immune binding activity of each monomolecular antibody.Results Five recombinant plasmids,PTS-ScFv-CL-CH_2-CH_3,PTS-ScFv-CH_2-CH_3,PTS-ScFv-CL-CH_2,PTS-ScFvCH_2,and PTS-ScFv-CL,were constructed.After transfection into E.coli BL21(DE3) and purification,the corresponding monomolecular antibodies,ScFv-CL-CH_2-CH_3,ScFv-CH_2-CH_3,ScFv-CL-CH_2,ScFv-CH_2,and ScFv-CL,were obtained,which had the relative molecular mass of about 60 000,and the concentrations of about 1 mg/mL.Among them,ScFv-CH_2-CH_3showed the highest immune binding activity,and the A_(450) value reached 3.9,much higher than the other four monomolecular antibodies,with the concentration of about 1 mg/mL and the purity about 86%.Conclusion A fully human monomolecular antibody ScFv-CH_2-CH_3 with high affinity,low immunogenicity and internalization activity was obtained,which lays a foundation for the further study of therapeutic antibody against CPA.

Generation and characterization of humanized monoclonal antibody against human IFNAR1 / 中国药科大学学报

@#Abstract: Type I interferons play an important role in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). Monoclonal antibody shows therapeutic potential by blocking the signaling pathway. This study used recombinant human subunit 1 of the type I interferon receptor (IFNAR1) protein to immunize New Zealand white rabbits, and applied B cell cloning technology to screen and obtain rabbit parental antibodies. After humanization modification, QX006N was obtained. In vitro biological studies showed that QX006N could specifically bind to human IFNAR1 with an affinity of 108 pmol/L, and neutralize the type I interferon signaling pathway and this pathway mediated biological effects. This study provides a solid foundation for the development of antibody drugs targeting the type I interferon signaling pathway for the treatment of SLE.

A study on the ethical issues of using reproductive human cloning as living donors in Never Let Me Go / 中国医学伦理学

Kazuo Ishiguro，the Nobel Prize winner in Literature，is among one of those intellectuals who concerns greatly about the ethical issues in organ transplantation. A “utopia” of organ transplantation in which reproductive human clones are used as living donors is fictionalized in his first science fiction Never Let Me Go. The ethical issues of donors，especially those caused by using reproductive human cloning as living donors，is an important theme explored by the author. Based on the basic principles of bioethics，this paper aims to present the relevant ethical issues from the following three dimensions：the examination of ethical problems in using reproductive human cloning as donors，the interpretation of the medical circumstances of reproductive human cloning donors and the analysis of the ethical responsibilities for the tragedy of reproductive human cloning donors. From the perspective of donor source，the ethical problems of using reproductive cloning as living donors are mainly manifested in the serious harms done to the clones and the violation of their dignity as human beings. By investigating the donors’ medical circumstances，it is clear that the reproductive human clones do not enjoy the right of informed consent that donors should have while donating organs is not their complete independent decision and their risk-benefit ratio as donors in the process of organ transplantation has not been carefully evaluated. In terms of ethical responsibility for their tragedy，the health care providers’ indifference to and trampling on the value as well as the dignity of reproductive human cloning is the direct cause，the policy made by the governmental decision-makers who follow the principle of “technological imperative”the important cause while general public’s lack of consciousness in technical ethics and their pursuit of short-sighted utilitarianism principle the basic cause.

Phylo-geographic analysis of whitefly on the basis of mitochondrial cytochrome oxidase 1 gene / Análise filogeográfica da mosca-branca com base no gene citocromo oxidase 1 mitocondrial

Bemisia tabaci is a species complex that causes damage to its broad range of plant hosts through serious feeding. It transmits plant viruses of different groups to important agricultural crops. Some important cash crops of Pakistan are sugar cane, rice, tobacco and seed oil. It shows high genetic variability and is differentiated as races or biotypes. Biotypes are, biotype Q, biotype B, biotype B2, biotype M, biotype L, biotype A, biotype H, biotype C, biotype K, biotype N, biotype R, biotype E, biotype P, biotype J, biotype S, biotype AN. Although the current report based on the Bayesian study of mitochondrial cytohrome oxidase gene1 (CO1) DNA sequences has classified the different populations of whiteflies into twelve genetic groups which are Mediterranean, Sub-Saharan Africa silverleafing, Indian Ocean, Asia II, Asia I, Australia, New World, Italy, China, Sub-Saharan Africa non-silverleafing, Mediterranean/Asia Minor/Africa and Uganda sweet potato. Begomoviruses is largest group of viruses transmitted by B. tabaci and cause major diseases of crops such as tomato and chili leaf curl disease, cassava mosaic disease; yellow mosaic disease of legumes and cotton leaf curl disease. The main objective of current study is to inculpate knowledge regarding genetic diversity of whitefly in cotton fields across Pakistan via analysis of partial DNA sequence of mitochondrial gene Cytochrom Oxidase I (mtCO1).

Bemisia tabaci é um complexo de espécies que causa danos a uma ampla gama de hospedeiros vegetais por meio de alimentação séria. Ele transmite vírus de plantas de diferentes grupos para importantes safras agrícolas. Algumas safras comerciais importantes do Paquistão são cana-de-açúcar, arroz, tabaco e óleo de semente. Apresenta alta variabilidade genética e é diferenciado em raças ou biótipos. Os biótipos são: biótipo Q, biótipo B, biótipo B2, biótipo M, biótipo L, biótipo A, biótipo H, biótipo C, biótipo K, biótipo N, biótipo R, biótipo E, biótipo P, biótipo J, biótipo S, biótipo AN . Embora o relatório atual baseado no estudo bayesiano das sequências de DNA do gene 1 da oxidase do citocromo mitocondrial (CO1) tenha classificado as diferentes populações de moscas-brancas em doze grupos genéticos, que são Mediterrâneo, África Subsaariana com folha de prata, Oceano Índico, Ásia II, Ásia I, Austrália, Novo Mundo, Itália, China, África Subsaariana sem folha prateada, Batata-doce Mediterrâneo / Ásia Menor / África e Uganda. Os begomovírus são o maior grupo de vírus transmitidos por B. tabaci e causam as principais doenças de culturas, como a doença do cacho do tomate e da pimenta-malagueta, doença do mosaico da mandioca, doença do mosaico amarelo de leguminosas e doença do enrolamento da folha do algodão. O principal objetivo do presente estudo é inculpar conhecimento sobre a diversidade genética da mosca-branca em campos de algodão em todo o Paquistão por meio da análise da sequência parcial de DNA do gene mitocondrial Citocromo Oxidase I (mtCO1).

Phylo-geographic analysis of whitefly on the basis of mitochondrial cytochrome oxidase 1 gene

Abstract Bemisia tabaci is a species complex that causes damage to its broad range of plant hosts through serious feeding. It transmits plant viruses of different groups to important agricultural crops. Some important cash crops of Pakistan are sugar cane, rice, tobacco and seed oil. It shows high genetic variability and is differentiated as races or biotypes. Biotypes are, biotype Q, biotype B, biotype B2, biotype M, biotype L, biotype A, biotype H, biotype C, biotype K, biotype N, biotype R, biotype E, biotype P, biotype J, biotype S, biotype AN. Although the current report based on the Bayesian study of mitochondrial cytohrome oxidase gene1 (CO1) DNA sequences has classified the different populations of whiteflies into twelve genetic groups which are Mediterranean, Sub-Saharan Africa silverleafing, Indian Ocean, Asia II, Asia I, Australia, New World, Italy, China, Sub-Saharan Africa non-silverleafing, Mediterranean/Asia Minor/Africa and Uganda sweet potato. Begomoviruses is largest group of viruses transmitted by B. tabaci and cause major diseases of crops such as tomato and chili leaf curl disease, cassava mosaic disease; yellow mosaic disease of legumes and cotton leaf curl disease. The main objective of current study is to inculpate knowledge regarding genetic diversity of whitefly in cotton fields across Pakistan via analysis of partial DNA sequence of mitochondrial gene Cytochrom Oxidase I (mtCO1).

Resumo Bemisia tabaci é um complexo de espécies que causa danos a uma ampla gama de hospedeiros vegetais por meio de alimentação séria. Ele transmite vírus de plantas de diferentes grupos para importantes safras agrícolas. Algumas safras comerciais importantes do Paquistão são cana-de-açúcar, arroz, tabaco e óleo de semente. Apresenta alta variabilidade genética e é diferenciado em raças ou biótipos. Os biótipos são: biótipo Q, biótipo B, biótipo B2, biótipo M, biótipo L, biótipo A, biótipo H, biótipo C, biótipo K, biótipo N, biótipo R, biótipo E, biótipo P, biótipo J, biótipo S, biótipo AN . Embora o relatório atual baseado no estudo bayesiano das sequências de DNA do gene 1 da oxidase do citocromo mitocondrial (CO1) tenha classificado as diferentes populações de moscas-brancas em doze grupos genéticos, que são Mediterrâneo, África Subsaariana com folha de prata, Oceano Índico, Ásia II, Ásia I, Austrália, Novo Mundo, Itália, China, África Subsaariana sem folha prateada, Batata-doce Mediterrâneo / Ásia Menor / África e Uganda. Os begomovírus são o maior grupo de vírus transmitidos por B. tabaci e causam as principais doenças de culturas, como a doença do cacho do tomate e da pimenta-malagueta, doença do mosaico da mandioca, doença do mosaico amarelo de leguminosas e doença do enrolamento da folha do algodão. O principal objetivo do presente estudo é inculpar conhecimento sobre a diversidade genética da mosca-branca em campos de algodão em todo o Paquistão por meio da análise da sequência parcial de DNA do gene mitocondrial Citocromo Oxidase I (mtCO1).

Cloning and functional analysis of flavanone 3-hydroxylase gene in Rhododendron hybridum Hort / 生物工程学报

Flavanone 3-hydroxylase (F3H) is a key enzyme in the synthesis of phycocyanidins. In this experiment, the petals of red Rhododendron hybridum Hort. at different developmental stages were used as experimental materials. The R. hybridum flavanone 3-hydroxylase (RhF3H) gene was cloned using reverse transcription PCR (RT-PCR) and rapid-amplification of cDNA ends (RACE) techniques, and bioinformatics analyses were performed. Petal RhF3H gene expression at different developmental stages were analyzed by using quantitative real-time polymerase chain reaction (qRT-PCR). A pET-28a-RhF3H prokaryotic expression vector was constructed for the preparation and purification of RhF3H protein. A pCAMBIA1302-RhF3H overexpression vector was constructed for genetic transformation in Arabidopsis thaliana by Agrobacterium-mediated method. The results showed that the R. hybridum Hort. RhF3H gene is 1 245 bp long, with an open reading frame of 1 092 bp, encoding 363 amino acids. It contains a Fe2+ binding motif and a 2-ketoglutarate binding motif of the dioxygenase superfamily. Phylogenetic analysis showed that the R. hybridum RhF3H protein is most closely related to the Vaccinium corymbosum F3H protein. qRT-PCR analysis showed that the expression level of the red R. hybridum RhF3H gene tended to increase and then decrease in the petals at different developmental stages, with the highest expression at middle opening stage. The results of the prokaryotic expression showed that the size of the induced protein of the constructed prokaryotic expression vector pET-28a-RhF3H was about 40 kDa, which was similar to the theoretical value. Transgenic RhF3H Arabidopsis thaliana plants were successfully obtained, and PCR identification and β-glucuronidase (GUS) staining demonstrated that the RhF3H gene was integrated into the genome of A. thaliana plants. qRT-PCR, total flavonoid and anthocyanin contentanalysis showed that RhF3H was significantly higher expressed in the transgenic A. thaliana relative to that of the wild type, and its total flavonoid and anthocyanin content were significantly increased. This study provides a theoretical basis for investigating the function of RhF3H gene, as well as for studying the molecular mechanism of flower color in R. simsiib Planch.

Cloning and expression profile of ZFP36L1 gene in goat / 生物工程学报

The purpose of this study was to clone and characterize the ZFP36L1 (zinc finger protein 36-like 1) gene, clarify its expression characteristics, and elucidate its expression patterns in different tissues of goats. Samples of 15 tissues from Jianzhou big-eared goats, including heart, liver, spleen, lung and kidney were collected. Goat ZFP36L1 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR), then the gene and protein sequence were analyzed by online tools. Quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression level of ZFP36L1 in intramuscular preadipocytes in different tissues and adipocytes of goat at different differentiation stages. The results showed that the length of ZFR36L1 gene was 1 224 bp, and the coding sequence (CDS) region was 1 017 bp, encoding 338 amino acids, which was a non-secretory unstable protein mainly located in nucleus and cytoplasm. Tissue expression profile showed that ZFP36L1 gene was expressed in all selected tissues. In visceral tissues, the small intestine showed the highest expression level (P < 0.01). In muscle tissue, the highest expression level was presented in longissimus dorsi muscle (P < 0.01), whereas the expression level in subcutaneous adipose tissue was significantly higher than that in other tissues (P < 0.01). The results of induced differentiation showed that the expression of this gene was up-regulated during adipogenic differentiation of intramuscular precursor adipocytes (P < 0.01). These data may help to clarify the biological function of the ZFP36L1 gene in goat.

Gene cloning and sequence analysis of the RPL29 gene and its effect on lipogenesis in goat intramuscular adipocytes / 生物工程学报

The aim of this study was to clone the goat RPL29 gene and analyze its effect on lipogenesis in intramuscular adipocytes. Using Jianzhou big-eared goats as the object, the goat RPL29 gene was cloned by reverse transcription-polymerase chain reaction (RT-PCR), the gene structure and expressed protein sequence were analyzed by bioinformatics, and the mRNA expression levels of RPL29 in various tissues and different differentiation stages of intramuscular adipocytes of goats were detected by quantitative real-time PCR (qRT-PCR). The RPL29 overexpression vector pEGFP-N1-RPL29 constructed by gene recombination was used to transfect into goat intramuscular preadipocytes and induce differentiation. Subsequently, the effect of overexpression of RPL29 on fat droplet accumulation was revealed morphologically by oil red O and Bodipy staining, and changes in the expression levels of genes related to lipid metabolism were detected by qRT-PCR. The results showed that the length of the goat RPL29 was 507 bp, including a coding sequence (CDS) region of 471 bp which encodes 156 amino acid residues. It is a positively charged and stable hydrophilic protein mainly distributed in the nucleus of cells. Tissue expression profiling showed that the expression level of this gene was much higher in subcutaneous adipose tissue and inter-abdominal adipose tissue of goats than in other tissues (P < 0.05). The temporal expression profile showed that the gene was expressed at the highest level at 84 h of differentiation in goat intramuscular adipocytes, which was highly significantly higher than that in the undifferentiated period (P < 0.01). Overexpression of RPL29 promoted lipid accumulation in intramuscular adipocytes, and the optical density values of oil red O staining were significantly increased (P < 0.05). In addition, overexpression of RPL29 was followed by a highly significant increase in ATGL and ACC gene expression (P < 0.01) and a significant increase in FASN gene expression (P < 0.05). In conclusion, the goat RPL29 may promote intra-muscular adipocyte deposition in goats by up-regulating FASN, ACC and ATGL.

Gene cloning and enzymatic activity analysis of phenylalanine ammonia-lyase from Sinopodophyllum hexandrum (Royle) Ying / 生物工程学报

Phenylalanine ammonia-lyase (PAL) is the key entry enzyme of plant phenylpropanoid pathway. It plays an important role in the biosynthesis of podophyllotoxin, an anti-tumor lignan that is currently produced from its main natural source Sinopodophyllum hexandrum (Royle) Ying. In this study, we cloned the gene ShPAL encoding phenylalanine ammonia-lyase by RT-PCR from the root of S. hexandrum ecotype inhabited in the Aba' district, Sichuan, based on its public SRA transcriptome data-package. Bioinformatics analyses showed that the ShPAL-encoded protein is composed of 711 amino acids, contains the conserved domains of PAL, and has the signature motif within the active center of aromatic ammonia-lyases. Moreover, ShPAL protein was predicted to have a secondary structure mainly composed of α-helix and random coil, a typical 'seahorse' shape monomer tertiary structure, and a homologous tetramer three-dimensional structure by Swiss-Modelling. The phylogenetic lineage analysis indicated ShPAL was of the highest sequence identity and the shortest evolutionary distance with the PAL of Epimedium sagittatum from the same Berberidaceae family. Subcellular localization experiments showed that ShPAL protein was mainly distributed in the cytoplasm, despite of a minority on the endoplasmic reticulum membrane. Furthermore, ShPAL protein was recombinantly expressed in Escherichia coli and purified by histidine-tag affinity chromatography. Its enzymatic activity was determined up to 20.91 U/mg, with the optimum temperature of 41 ℃ and pH of 9.0. In contrast, the enzyme activity of its F130H mutant decreased by about 23.6%, yet with the same trends of change with temperature and pH, confirming that phenylalanine at this position does affect the substrate specificity of PAL. Both the wild type and the mutant have relatively poor thermostability, but good pH-stability. These results may help to further investigate the regulatory role of PAL in the process of podophyllotoxin biosynthesis and advance the heterologous synthesis of podophyllotoxin to protect the germplasm resource of S. hexandrum. They also demonstrate that ShPAL has a potential application in biochemical industry and biomedicine.

Cloning and functional verification of PhAEP gene, a key enzyme for biosynthesis of heterophyllin A in Pseudostellaria heterophylla / 中国中药杂志

This paper aimed to study the role of asparagine endopeptidase(AEP) gene in the biosynthesis mechanism of cyclic peptide compounds in Pseudostellaria heterophylla. The transcriptome database of P. heterophylla was systematically mined and screened, and an AEP gene, tentatively named PhAEP, was successfully cloned. The heterologous function verification by Nicotiana benthamiana showed that the expression of the gene played a role in the biosynthesis of heterophyllin A in P. heterophylla. Bioinformatics analysis showed that the cDNA of PhAEP was 1 488 bp in length, encoding 495 amino acids with a molecular weight of 54.72 kDa. The phylogenetic tree showed that the amino acid sequence encoded by PhAEP was highly similar to that of Butelase-1 in Clitoria ternatea, reaching 80%. The sequence homology and cyclase active site analysis revealed that the PhAEP enzyme may specifically hydrolyse the C-terminal Asn/Asp(Asx) site of the core peptide in the HA linear precursor peptide of P. heterophylla, thereby participating in the ring formation of the linear precursor peptide. The results of real-time quantitative polymerase chain reaction(RT-qPCR) showed that the expression level of PhAEP was the highest in fruits, followed by in roots, and the lowest in leaves. The heterophyllin A of P. heterophylla was detected in N. benthamiana that co-expressed PrePhHA and PhAEP genes instantaneously. In this study, the PhAEP gene, a key enzyme in the biosynthesis of heterophyllin A in P. heterophylla, has been successfully cloned, which lays a foundation for further analysis of the molecular mechanism of PhAEP enzyme in the biosynthesis of heterophyllin A in P. heterophylla and has important significance for the study of synthetic biology of cyclic peptide compounds in P. heterophylla.

Cloning and Expression Analysis of Squalene Epoxidase Gene in Poria cocos / 中国实验方剂学杂志

ObjectiveTo clone squalene epoxidase （SE）， a potential key rate-limiting enzyme involved in the synthesis pathway of Poria cocos triterpenes， from P. cocos and analyze for bioinformatics and expression. MethodThe total RNA was extracted by the kit and reverse-transcribed to cDNA. Specific primers were designed， and the cDNA was used as a template for cloning the SE gene， which was analyzed for bioinformatics. The expression of P. cocos qualene epoxidase（PcSE） was examined by Real-time polymerase chain reaction（Real-time PCR） in P. coco Shenzhou No. 10， Xiangjing 28， and 5.78 strains. ResultThe full length of PcSE is 1 571 bp， containing four exons and three introns. The obtained CDS sequence is 1 413 bp， encoding 470 amino acids. This protein is a hydrophobic protein with no signal peptide structure and has two transmembrane structural domains with a FAD/NAD （P） binding domain and SE structural domain localized to the mitochondrial membrane and the plasma membrane. The homologous sequence alignment with fungi of the Poriferae family is 80.92%， and the phylogenetic tree shows that PcSE protein is most closely related to P. cocos from the US. The results of Real-time PCR showed that the PcSE was expressed in all three strains， with the highest expression in 5.78 strain， and there was no significant difference in PcSE expression among the three strains. ConclusionFor the first time， the PcSE gene was cloned and analyzed from P. cocos， providing a basis for further research on the function of PcSE and the analysis of P. cocos triterpene biosynthesis pathway.

Cloning and Expression Patterns of Coumarate-3-hydroxylase Gene from Angelica sinensis and Its Correlation with Content of Ferulic Acid / 中国实验方剂学杂志

ObjectiveTo clone coumarate-3-hydroxylase gene （C3H） from Angelica sinensis， and analyze the correlation between its bioinformatics， expression patterns and content of ferulic acid， and to explore the functions of ASC3H. MethodReal-time polymerase chain reaction （Real-time PCR） was used to clone the full-length cDNA of ASC3H based on the transcriptome dataset of A. sinensis， and the bioinformatics analysis of the gene sequence was carried out. Real-time PCR and high performance liquid chromatography （HPLC） were used to determine relative expression of ASC3H and content of ferulic acid in different root tissues of A. sinensis （periderm， cortex and stele）. ResultThe open reading frame （ORF） of ASC3H （GenBank accession number： MN2550298） was 1 530 bp， encoding 509 amino acids， with a theoretical molecular weight of 57.86 kDa and an isoelectric point of 8.36. It was a hydrophilic protein that was located in the chloroplast with multiple phosphorylation sites and a transmembrane region， and contained a conserved domain CGYDWPKGYGPIINVW_P450 （383-399 aa） in cytochrome P450. Multiple amino acid sequence alignment analysis showed that ASC3H had high similarity with C3H from other plants， especially Ammi majus in Umbelliferae. The Real-time PCR revealed that ASC3H had different expressions in periderm， cortex and stele tissues of A. sinensis roots. It was found from HPLC that the cortex tissues had the highest content of ferulic acid， and the stele tissues had the lowest. ConclusionASC3H was successfully cloned from A. sinensis， and its sequence characteristics were understood more clearly， suggesting that ASC3H might be involved in the ferulic acid biosynthesis pathway of A. sinensis. This paper provided a basis for further studying the functions of the gene and exploring the biosynthesis and regulation mechanism of ferulic acid in A. sinensis， while laying the foundation for the genetic improvement of A. sinensis．

Cloning and functional analysis of IPI gene from Fritillaria unibracteata Hsiao et K. C. Hsia / 药学学报

An open reading frame (ORF) of isopentenyl-diphosphate delta isomerase gene (FuIPI) was cloned from Fritillaria unibracteata Hsiao et K. C. Hsia. (F. unibracteata). Furthermore, the bioinformatics and functional analyses of FuIPI were performed in this study. The result showed that, the ORF of FuIPI gene was 825 bp, encoding a polypeptide of 274 amino acids in length, with a relative molecular mass of about 31 kD and a theoretical isoelectric point of 5.61. Sequence analysis showed that FuIPI contained conserved structural domains and key residues involved in the catalyzing process. The phylogenetic analysis exhibited that FuIPI was closely related to IPIs of Dendrobium officinale and Musa acuminate. Real-time PCR analysis showed that FuIPI was distributed in different tissues of F. unibracteata, but had the highest transcriptional level in leaves, followed by stems, bulbs, and flowers. Furthermore, the FuIPI protein was successfully expressed in Escherichia coli BL21(DE3). The purified FuIPI protein successfully catalyzed the conversion from isopentenyl diphosphate (IPP) to dimethylallyl pyrophosphate (DMAPP). The above results provided a theoretical basis for further investigation of the molecular role of FuIPI in the biosynthesis of alkaloids.

Prokaryotic expression, subcellular localization and enzymatic activity analysis of DXS gene from Platycodon grandiflorum / 药学学报

1-Deoxy-D-xylulose-5-phosphate synthase (DXS), the first key enzyme in 2-methyl-D-erythritol-4-phosphate (MEP) pathway, catalyzes the condensation of glyceraldehyde-3-phosphate with pyruvate to 1-deoxy-xylose-5-phosphate (DXP). In this study, PgDXS1, PgDXS2, and PgDXS3 genes were cloned from the root of Platycodon grandiflorum (P. grandiflorum). The open reading frame (ORF) of PgDXS1, PgDXS2, and PgDXS3 were 2 160, 2 208, and 2 151 bp in full length, encoding 719, 735, and 716 amino acids, respectively. Homologous alignment results showed a high identity of PgDXSs with DXS in Hevea brasiliensis, Datura stramonium and Stevia rebaudiana. The recombinant expression plasmids of pET-28a-PgDXSs were constructed and transformed into Escherichia coli (E. coli) BL21 (DE3) cells, and the induced proteins were successfully expressed. Subcellular localization results showed that PgDXS1 and PgDXS2 were mainly located in chloroplasts, and PgDXS3 was located in chloroplasts, nucleus and cytoplasm. The expression of three DXS genes in different tissues of two producing areas of P. grandiflorum were assayed via real-time fluorescence quantitative PCR, and the results showed that all of them were highly expressed in leaves of P. grandiflorum from Taihe. Under methyl jasmonate (MeJA) treatment, the expression levels of three PgDXS genes showed a trend of first decreasing and then increasing at different time points (3 - 48 h), and the activity of DXS showed a trend of first increasing and then decreasing in three tissues of P. grandiflorum. This study provides a reference for further elucidating the biological function of PgDXS in terpenoid synthesis pathway in P. grandiflorum.

Cloning, expression and activity analysises of chalcone synthase genes in Carthamus tinctorius / 中草药·英文版

OBJECTIVE@#Flavonoids are the bioactive compounds in safflower (Carthamus tinctorius), in which chalcone synthase (CHS) is the first limiting enzyme. However, it is unclear that which chalcone synthase genes (CHSs) are participated in flavonoids biosynthesis in C. tinctorius. In this study, the CHSs in the molecular characterization and enzyme activities were investigated.@*METHODS@#Putative chalcone biosynthase genes were screened by the full-length transcriptome sequences data in C. tinctorius. Chalcone biosynthase genes in C. tinctorius (CtCHSs) were cloned from cDNA of flowers of C. tinctorius. The cloned gene sequences were analyzed by bioinformatics, and their expression patterns were analyzed by real-time PCR (RT-PCR). The protein of CtCHS in the development of flowers was detected by polyclonal antibody Western blot. A recombinant vector of CtCHS was constructed. The CtCHS recombinant protein was induced and purified to detect the enzyme reaction (catalyzing the reaction of p-coumaryl-CoA and malonyl-CoA to produce naringin chalcone). The reaction product was detected by HPLC and LC-MS.@*RESULTS@#Two full-length CtCHS genes were successfully cloned from the flowers of safflower (CtCHS1 and CtCHS3), with gene lengths of 1525 bp and 1358 bp, respectively. RT-PCR analysis showed that both genes were highly expressed in the flowers, but the expression of CtCHS1 was higher than that of CtCHS3 at each developmental stage of the flowers. WB analysis showed that only CtCHS1 protein could be detected at each developmental stage of the flowers. HPLC and LC-MS analyses showed that CtCHS1 could catalyze the conversion of p-coumaryl-CoA and malonyl-CoA substrates to naringin chalcone.@*CONCLUSION@#CtCHS1 is involved in the biosynthesis of naringin chalcone in safflower.

Cloning, expression, purification and preliminary oligomerisation analysis of recombinant protein Mycobacterium tuberculosis Rv1288

Aims@#LysM containing-protein is widely distributed in all domains of life and this kind of protein is essential for various biological activities in living organisms. Rv1288, a LysM containing-protein with esterase, was found in Mycobacterium tuberculosis. Biophysical studies revealed that the protein is responsible for modulating lipid metabolism that enables pathogens to survive under extreme conditions and decrease the permeability of the pathogen’s cell wall to drug therapeutic agents. However, recognition and interaction between the protein, lipid and carbohydrate moieties at the molecular level remains largely unknown and must be investigated. Therefore, a production of recombinant protein Rv1288 should be performed to aid the study.@*Methodology and results@#In this study, we cloned the full-length cDNA of Rv1288 from M. tuberculosis strain H37Rv and expressed it in pET-24d- Escherichia coli BL21(DE3) cells. Affinity and size exclusion chromatography methods purified the protein, and its preliminary oligomerisation state was determined based on a calculated apparent molecular weight of the protein. Rv1288 was expressed as a soluble protein at 20 °C, induced with 1 mM of isopropyl β-D-1-thiogalactopyranoside (IPTG). The calculated apparent molecular weight suggested that the Rv1288 protein formed a hexamer in solution. @*Conclusion, significance and impact of study@#All the methods involved in this study to produce the recombinant Rv1288-pET24d and its soluble protein in E. coli cells have been described. Hence, it can be implemented for future studies.

Construction a shuttle vector containing AaCPR100A epidermal protein gene of Aedes aegypti with two spore-producing-dependent promoters in Bacillus thuringiensis by in-fusion cloning / 中国热带医学

@#Abstract: Objective To construct a shuttle vector pHT315-AaCPR100A with two spore-producing-dependent promoters and the target gene AaCPR100A in Escherichia coli-Bacillus thuringiensis. Methods The forward promoter of Cry3A, named Pro-1 (+), was amplified by PCR using pSVP27A plasmid as the template, and the target gene AaCPR100A was amplified using Aedes aegypti RNA reverse conversion cDNA as the template. The plasmid pHT315 was linearized by digestion with Hind Ⅲ and Sal Ⅰ. The forward promoter and the target gene were inserted into the linearized vector pHT315 successively by in-fusion cloning according to the transcription direction. The synthesized plasmid containing the Cry3A reverse promoter sequence was used as the template, and the Pro-1 (-) reverse promoter was amplified by PCR. The intermediate vector containing the forward promoter and the target gene was linearized by EcoR I restriction enzyme, and the reverse promoter was inserted downstream of the target gene by in-fusion cloning in the direction of transcription. Results By agarose gel electrophoresis, the forward promoter, target gene AaCPR100A and reverse promoter bands were clear and of good quality, which could be used for in-fusion cloning experiments. The two spore-producing-dependent promoters and target gene fragments were connected by In-fusion cloning. The recombinant vector pHT315-AaCPR100A was verified by PCR. The forward promoter, target gene fragment and reverse promoter were successfully amplified in the recombinant vector. Nucleotide sequencing verified that the sequencing results of the bidirectional promoter sequence and the target gene sequence were basically consistent with the sequence alignment results, which met the requirements of the construction of vector elements and proved that the recombinant vector was successfully constructed. Conclusions Based on the above results, this study proves that the recombinant shuttle vector with two spore-producing-dependent promoters can be successfully constructed by in-fusion cloning technology, laying the foundation for the construction of engineered Bacillus thuringiensis expressing dsRNA of AaCPR100A.

Analyzing the evolution of insect TMED gene and the expression pattern of silkworm TMED gene / 生物工程学报

Transmembrane emp24 domain (TMED) gene is closely related to immune response, signal transduction, growth and disease development in mammals. However, only the Drosophila TMED gene has been reported on insects. We identified the TMED family genes of silkworm, Tribolium castaneum, tobacco moth and Italian bee from their genomes, and found that the TMED family gene composition patterns of one α-class, one β-class, one δ-class and several γ-classes arose in the common ancestor of pre-divergent Hymenoptera insects, while the composition of Drosophila TMED family members has evolved in a unique pattern. Insect TMED family γ-class genes have evolved rapidly, diverging into three separate subclasses, TMED6-like, TMED5-like and TMED3-like. The TMED5-like gene was lost in Hymenoptera, duplicated in the ancestors of Lepidoptera and duplicated in Drosophila. Insect TMED protein not only has typical structural characteristics of TMED, but also has obvious signal peptide. There are seven TMED genes in silkworm, distributed in six chromosomes. One of seven is single exon and others are multi-exons. The complete open reading frame (ORF) sequences of seven TMED genes of silkworm were cloned from larval tissues and registered in GenBank database. BmTMED1, BmTMED2 and BmTMED6 were expressed in all stages and tissues of the silkworm, and all genes were expressed in the 4th and 5th instar and silk gland of the silkworm. The present study revealed the composition pattern of TMED family members, their γ class differentiation and their evolutionary history, providing a basis for further studies on TMED genes in silkworm and other insects.

Cloning and expression analysis of wpHSP90 gene from Whitmania pigra at different temperatures / 中国中药杂志

HSP90 is a widely distributed molecular chaperone that participates in a variety of cellular processes and plays an important role in the meiosis of germ cells. However, its role in the gonadal development of hermaphroditic Whitmania pigra is not yet clear. To explore the effect of HSP90 on the germ cell development of Wh. Pigra, this study cloned the wpHSP90 gene, performed bioinformatics analysis, and measured its expression levels. The results showed that the cloned wpHSP90 was 2 592 bp in length, with an open reading frame(ORF) of 2 373 bp, encoding 790 amino acids. Prediction analysis revealed 85 phosphorylation modification sites on serine, threonine, and tyrosine residues of the wpHSP90 protein. Structural domain prediction and multiple sequence alignment results showed that wpHSP90 contained two conserved domains of HSP90 and exhibited the highest homology with Helobdella robusta, with a sequence similarity of 80.72%. RT-qPCR results showed that the relative expression level of wpHSP90 in the gonads of 5-month-old Wh. pigra was positively correlated with temperature within the range of 12 ℃ to 28 ℃. The expression level in the female gonads was significantly higher than in the male gonads and correlated with the trend of germ cell development in the ovaries and testes. In conclusion, wpHSP90 may be involved in regulating the development of germ cells, particularly oocytes, in Wh. pigra. This study provides a reference for further research on the gonadal development mechanism in Wh. pigra.

Cloning and expression analysis of ANR genes from different species of Lonicera japonica Thunb / 药学学报

Anthocyanidin reductase (ANR) is one of the key enzyme in the flavonoid biosynthetic pathway, and its catalytic activity is important for the synthesis of plant anthocyanin. In this study, specific primers were designed according to the transcriptome data of Lonicera japonica Thunb., and the CDS, gDNA and promoter sequences of ANR genes from Lonicera japonica Thunb. and Lonicera japonica Thunb. var. chinensis (Wats.) Bak. were cloned. The results showed that the CDS sequences of LjANR and rLjANR were 1 002 bp, the gDNA sequences were 2 017 and 2 026 bp respectively, and the promoter sequences were 1 170 and 1 164 bp respectively. LjANR and rLjANR both contain 6 exons and 5 introns, which have the same length of exons and large differences in introns. The promoter sequences both contain a large number of light response, hormone response and abiotic stress response elements. Bioinformatics analysis showed that both LjANR and rLjANR encoded 333 amino acids and were predicted to be stable hydrophobic proteins without transmembrane segments and signal peptides. The secondary structures of LjANR and rLjANR were predicted to be mainly consisted of α-helix and random coil. Sequence alignment and phylogenetic analysis showed that LjANR and rLjANR had high homology with Actinidia chinensis var. chinensis, Camellia sinensis and Camellia oleifera, and were closely related to them. The expression levels of LjANR and rLjANR were the highest in flower buds and the lowest in roots. The expression patterns at different flowering stages were similar, with higher expression levels in S1 and S2 stages and then gradually decreased until reaching the lowest level in S4 stage, after a slow increase in S5 stage, the expression levels decreased again. The expression levels of ANR genes in the two varieties showed significant differences in roots, S2 and S5 stages, while the differences in stems, flower buds, S1, S3 and S6 stages were extremely significant. The prokaryotic expression vector pET-32a-LjANR was constructed for protein expression. The target protein was successfully expressed of about 59 kD. This study lays a foundation for further study on the function of ANR gene and provides theoretical guidance for breeding new varieties of Lonicera japonica Thunb.