1.Prokaryotic expression, purification and functional identification of epidermal pattern factors in Arabidopsis thaliana.
Zhuping JIN ; Cheng LI ; Lei WANG ; Yanxi PEI
Chinese Journal of Biotechnology 2020;36(4):792-800
Stomatal density is important for crop yield. In this paper, we studied the epidermal pattern factors (EPFs) related to stomatal development. Prokaryotic expression vectors were constructed to obtain EPFs. Then the relationship between EPFs and hydrogen sulfide (H2S) was established. First, AtEPF1, AtEPF2 and AtEPFL9 were cloned and constructed to pET28a vectors. Then recombinant plasmids pET28a-AtEPF1, pET28a-AtEPF2 and pET28a-AtEPFL9 were digested and sequenced, showing successful construction. Finally, they were transformed into E. coli BL21(DE3) separately and induced to express by isopropyl β-D-galactoside (IPTG). The optimized expression conditions including IPTG concentration (0.5, 0.3 and 0.05 mmol/L), temperature (28 °C, 28 °C and 16 °C) and induction time (16 h, 16 h and 20 h) were obtained. The bands of purified proteins were about 18 kDa, 19 kDa and 14.5 kDa, respectively. In order to identify their function, the purified AtEPF2 and AtEPFL9 were presented to Arabidopsis thaliana seedlings. Interestingly, the H2S production rate decreased or increased compared with the control, showing significant differences. That is, EPFs affected the production of endogenous H2S in plants. These results provide a foundation for further study of the relationship between H2S and EPFs on stomatal development, but also a possible way to increase the yield or enhance the stress resistance.
Arabidopsis
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genetics
;
metabolism
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Arabidopsis Proteins
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genetics
;
isolation & purification
;
metabolism
;
Escherichia coli
;
genetics
;
Genetic Vectors
;
genetics
;
Hydrogen Sulfide
;
metabolism
;
Plasmids
;
genetics
;
Seedlings
;
metabolism
2.Cloning, expression, and purification of c-di-AMP metabolism-related genes from Porphyromonas gingivalis.
Wei QIU ; Xingqun CHENG ; Xuedong ZHOU ; Yuqing LI
West China Journal of Stomatology 2015;33(6):607-612
OBJECTIVETo clone, express, and purify cyclic diadenosine monophosphate (c-di-AMP) metabolism-related genes from Porphyromonas gingivalis (P. gingivalis) ATCC33277.
METHODSPolymerase chain reaction (PCR) from the genome of P. gingivalis ATCC33277 amplified, the coding regions of pgn0523, pgn1187, and pgn2003 genes. The amplified DNA fragments were ligated with a prokaryotic expression vector pET28a to construct the recombinant expression plasmids pET-pgn0523, pET-pgn1187, and pET-pgn2003. These recombinant plasmids were transformed into Escherichia coli (E. coli) BL21 (DE3) competent cells. The expression of recombinant proteins was induced by isopropyl-β-D-thiogalactoside and detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were purified using a Ni²⁺ matrix column, and their concentrations were determined by a BCA Protein Quantitative Kit.
RESULTSThe c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 were amplified successfully with the correct molecular size. The recombinant expression vectors were constructed by ligating enzyme-digested PCR products and pET28a vector, and verified by PCR and sequencing. After induction and purification, recombinant proteins were expressed successfully and obtained with the correct molecular size (19.5 x 10³, 39.9 x 10³, 66.0 x 10³). The final protein concentrations were 0.708, 0.523, and 0.861 mg · mL⁻¹ after dialysis.
CONCLUSIONThe c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 are cloned successfully, and their coding products are expressed correctly in E. coli. High-purity proteins are finally obtained. The cloning and purification of these important proteins will help us to further investigate the physiological function and regulatory mechanism of c-di-AMP signaling system in P. gingivalis.
Bacterial Proteins ; biosynthesis ; genetics ; isolation & purification ; Cloning, Molecular ; Dinucleoside Phosphates ; Escherichia coli ; genetics ; Genetic Vectors ; Plasmids ; Polymerase Chain Reaction ; Porphyromonas gingivalis ; genetics ; Recombinant Proteins
3.Construction and Identification of the Bait Vector Containing Duck Circovirus Cap Gene for the Yeast Two-hybrid System.
Yu XU ; Zhilong ZHANG ; Yanyan LU ; Lei ZHANG ; Pengfei LI ; Renyong JIA
Chinese Journal of Virology 2015;31(3):282-286
To construct a bait expression vector containing the duck circovirus Cap gene for use in the yeast two-hybrid system, the whole cap codon-optimized gene was inserted into pGBKT7 vector and confirmed by PCR, restriction enzyme digestion, and sequence analysis. After transformation into a Y2HGold yeast strain, the expression of Cap protein was analyzed by Western blotting. Toxicity and self-activation of the bait protein were detected using different dropout minimal base. PCR reaction, restriction enzyme digestion, and sequencing analyses indicated that the duck circovirus Cap gene was correctly inserted into pG- BKT7. Western blotting showed that the whole Cap protein was expressed. The recombinant bait protein had no toxicity and self-activation. Therefore, the bait vector with the Cap gene was constructed successfully, providing a foundation for future screening for interacting proteins in the yeast two-hybrid system.
Animals
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Capsid Proteins
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genetics
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metabolism
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Circovirus
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classification
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genetics
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isolation & purification
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Cloning, Molecular
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Ducks
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Genetic Vectors
;
genetics
;
metabolism
;
Recombinant Fusion Proteins
;
genetics
;
metabolism
;
Saccharomyces cerevisiae
;
genetics
;
metabolism
;
Two-Hybrid System Techniques
4.Expression and activity determination of recombinant capsid protein VP2 gene of enterovirus type 71.
Xueyong HUANG ; Guohua LIU ; Xiaoning HU ; Yanhua DU ; Xingle LI ; Yuling XU ; Haomin CHEN ; Bianli XU
Chinese Journal of Preventive Medicine 2014;48(4):324-327
OBJECTIVETo clone and express the recombinant capsid protein VP2 of enterovirus type 71 (EV71) and to identify the immune activity of expressed protein in order to build a basis for the investigation work of vaccine and diagnostic antigen.
METHODSVP2 gene of EV71 was amplified by PCR, and then was cut by restriction enzyme and inserted into expression vector pMAL-c2X. The positive recombinants were transferred into E.coli TB1, the genetically engineered bacteria including pMAL-c2X-VP2 plasmids were induced by isopropyl thiogalactoside ( IPTG) , and the expression products were analyzed by SDS-PAGE and western blotting method. EV71 IgM antibody detection method by ELISA was set up, and the sensitivity and specificity of this method was assessed; 60 neutralizing antibody positive serum samples from hand foot and mouth disease (HFMD) patients were determined, of which 52 samples were positive and 8 samples were negative; a total of 88 acute phase serum samples of HFMD patients diagnosed in clinical were also detected.
RESULTSVP2 gene of 762 bp was obtained by PCR, the gene segment inserted into the recombinant vector was identified using restriction enzyme digestion. The recombinant vector could express a specific about 71 500 fusion protein in E.coli by SDS-PAGE. The purified recombinant protein of EV71-VP2 can react with the serum of HFMD patients to produce a specific band by western blotting. The sensitivity and specificity of ELISA was 87% and 83%, respectively. Of the 88 acute phase serum samples from children with HFMD, 48 samples (55%) were positive by the ELISA assay.
CONCLUSIONSVP2 gene of EV71 has been cloned and a prokaryotic high expression system for VP2 gene was successfully constructed in the present study. The recombination EV71-VP2 has well antigenicity, which could be useful for developing diagnose reagent or vaccine of EV71.
Antibodies, Neutralizing ; blood ; Antibodies, Viral ; blood ; Capsid Proteins ; genetics ; immunology ; Enterovirus A, Human ; genetics ; immunology ; isolation & purification ; Enzyme-Linked Immunosorbent Assay ; Genetic Vectors ; Hand, Foot and Mouth Disease ; immunology ; Humans ; Immunoglobulin M ; blood ; Recombinant Proteins ; genetics ; immunology
5.Improvement of yield and purity of human fibroblast growth factor-21.
Dan YU ; Xianlong YE ; Guiping REN ; Pengfei XU ; Shujie LI ; Zeshan NIU ; Deshan LI
Chinese Journal of Biotechnology 2014;30(4):658-668
Fibroblast growth factor -21 (FGF-21) is a recently discovered metabolic regulation factor, regulating glucose and lipid metabolism and increasing insulin sensitivity. FGF-21 is expected to be a potential anti-diabetic drug. Expression of FGF-21 as inclusion bodies has advantages for high yield and purity, but the bioactivity of the protein is almost totally lost after denature and renature. That is why FGF-21 is currently expressed in soluble form. As a result, the yield is considerably low. In this study, we used SUMO vector to express SUMO-human FGF-21 (SUMO-hFGF-21) in form of inclusion body. We optimized the culture conditions to increase the yield of the bioactive human fibroblast growth factor-21. We applied the hollow fiber membrane filtration column to enrich the bacteria, wash, denature and renature inclusion bodies. After affinity and gel filtration chromatography, we examined the hypoglycemic activity of FGF-21 by the glucose uptake assay in HepG2 cells. We also detected the blood glucose concentration of type 2 diabetic db/db model mice after short or long-term treatment. The results show that the yield of ihFGF-21 was 4 times higher than that of shFGF-21. The yield was 20 mg/L for ihFGF-21 vs. 6 mg/L for shFGF-21. The purity of ihFGF-21 was above 95%, while shFGF-21 was 90%. Compared with the traditional method of extracting inclusion bodies, the production cycle was about three times shortened by application of hollow fiber membrane filtration column technology, but the bioactivity did not significantly differ. This method provides an efficient and cost-effective strategy to the pilot and industrial production of hFGF-21.
Animals
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Bacteria
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metabolism
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Diabetes Mellitus, Experimental
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drug therapy
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Disease Models, Animal
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Fibroblast Growth Factors
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biosynthesis
;
Genetic Vectors
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Glucose
;
metabolism
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Hep G2 Cells
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Humans
;
Hypoglycemic Agents
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isolation & purification
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Inclusion Bodies
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metabolism
;
Mice
;
Recombinant Fusion Proteins
;
biosynthesis
;
Small Ubiquitin-Related Modifier Proteins
;
biosynthesis
6.Antibody preparation and enzyme linked immunosorbent assay of Lonicera japonica phenylalnine ammonia lyase.
Zhou-yong WANG ; Lu-qi HUANG ; Yuan YUAN ; Bao-min WANG
Acta Pharmaceutica Sinica 2013;48(9):1498-1502
The expression of phenylalnine ammonia lyase (LJPAL1) is closely related to the content of active compounds in Lonicera japonica. In this paper, a prokaryotic expression vector is constructed and LJPAL1 protein is expressed in E. coli. Three antigen sites were synthesized to peptide antigen and prepared polyclonal antibody of Anti-LJT-1, Anti-LJT-2 and Anti-LJT-3, separately. Antibody Anti-LJT-2 was screened using Western blotting. And indirect ELISA was built using Anti-LJT-2. The results of this study will be a base for honeysuckle chemical quality and evaluation kits.
Antibodies
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immunology
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metabolism
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Antibody Specificity
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Blotting, Western
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Enzyme-Linked Immunosorbent Assay
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Escherichia coli
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genetics
;
metabolism
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Flowers
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chemistry
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Gene Expression Regulation, Plant
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Genetic Vectors
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Lonicera
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chemistry
;
Phenylalanine Ammonia-Lyase
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chemistry
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immunology
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isolation & purification
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Plants, Medicinal
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chemistry
;
Plasmids
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Protein Structure, Secondary
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Protein Structure, Tertiary
7.Construction of prokaryotic expression vector, expression and purification of ginseng Cu/Zn superoxide dismutase.
Hong-Mei LIN ; Ze-Yu WANG ; Yue SHAO ; Xiao-Ye QIN ; Shi-Chao LIU ; Xin ZHANG ; Li-Min YANG
China Journal of Chinese Materia Medica 2013;38(23):4052-4055
The total RNA was extracted from ginseng leaves of Panax ginseng. The Cu/Zn-SOD gene was amplified via RT-PCR and the pET-28(a)-Cu/Zn-SOD expression vector was constructed. The pET-28 (a)-Cu/Zn-SOD recombinant plasmid was transformed into Escherichia coli BL21 (DE3) competent cells and was induced by IPTG in order to select optimal induction of expression conditions. The target protein was purified by the nickel ions (Ni ) affinity chromatography and the target protein enzyme activity was determinated by the xanthine oxidase method. The similarity of the Cu/Zn-SOD gene sequences and the Cu/Zn-SOD gene sequences of Korean ginseng in NCBI was 99. 00%. The target protein expression level was about 44.42%, and the molecular weight was 16.30 kDa after the pET-28(a)-Cu/Zn-SOD recombinants were induced by IPTG. The purified Cu/Zn-SOD protease activity reached 10,596.69 U x mg(-1). The P. ginseng pET-28(a)-Cu/Zn-SOD prokaryotic expression vector was built by the method of molecular biology, which provided the foundation for studying the Cu/Zn-SOD biology function.
Cloning, Molecular
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Escherichia coli
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genetics
;
Gene Expression
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Genetic Engineering
;
methods
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Genetic Vectors
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genetics
;
Panax
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enzymology
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genetics
;
Sequence Analysis
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Superoxide Dismutase
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genetics
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isolation & purification
;
metabolism
8.Expression analysis of glycosyltransferase BcUGT1 from Bupleurum chinense DC. and its expression in E. coli and the target protein purification.
Yun-Wen TAO ; Jie-Sen XU ; Jian-He WEI ; Jing SUN ; Yan-Hong XU ; Xin YANG ; Yan ZHANG ; Juan LIU ; Chun SUI
Acta Pharmaceutica Sinica 2013;48(8):1345-1352
The ORF sequence of glycosyltransferase gene BcUGT1 cloned from Bupleurum chinense DC. was analyzed and its three dimentional structure was predicted. Using qRT-PCR method, the expression characteristics of BcUGT1 after methyl jasmonate (MeJA) induction and in different plant tissues were investigated. The results showed that BcUGT1 may be involved in saikosaponin biosynthesis in B. chinense. Thereafter, the recombinant vectors of BcUGT1 were constructed for its expression in E. coli. The target protein was successfully expressed and purified. In the present study, three vectors, pRSET-A, pET-28a (+) and pET-30a (+), and three isolates of E. coli, BL21 (DE3) plysS, BL21A1 and BL21-CodonPlus (DE3)-RIPL were used under different induction conditions, such as different concentrations and during times of inducers (L-arabinose and IPTG) and different inducing temperatures. The results showed that in the condition of 0.5 or 1 mmol x L(-1) IPTG, 16 degrees C, 20 h, target protein expressed in BL21-CodonPlus (DE3)-RIPL with pET-28a (+) or pET-30a (+) as vector. Using PrepEase His-tagged protein purification kit, the target protein was purified. The present work will be helpful for follow-up bio-function analysis of BcUGT1.
Amino Acid Sequence
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Base Sequence
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Bupleurum
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chemistry
;
Cloning, Molecular
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DNA, Complementary
;
genetics
;
DNA, Plant
;
genetics
;
Escherichia coli
;
genetics
;
metabolism
;
Genetic Vectors
;
Glycosyltransferases
;
genetics
;
isolation & purification
;
metabolism
;
Oleanolic Acid
;
analogs & derivatives
;
biosynthesis
;
Open Reading Frames
;
genetics
;
Phylogeny
;
Plants, Medicinal
;
chemistry
;
Protein Structure, Secondary
;
Recombinant Fusion Proteins
;
genetics
;
metabolism
;
Saponins
;
biosynthesis
9.Efficient expression and purification of Fc-fragment-binding domain and its application to immunoglobulin G purification.
Xing Zhen LAO ; Ya Li ZHOU ; Heng ZHENG
Biomedical and Environmental Sciences 2013;26(11):916-919
Base Sequence
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Binding Sites, Antibody
;
Biochemistry
;
methods
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Electrophoresis, Polyacrylamide Gel
;
Enzyme-Linked Immunosorbent Assay
;
Escherichia coli
;
genetics
;
Genetic Vectors
;
Immunoglobulin Fc Fragments
;
genetics
;
metabolism
;
Immunoglobulin G
;
genetics
;
metabolism
;
Ligands
;
Molecular Sequence Data
;
Plasmids
;
Protein Binding
;
Recombinant Fusion Proteins
;
genetics
;
isolation & purification
;
Staphylococcal Protein A
;
genetics
;
metabolism
10.Construction of eukaryotic expression vector of SPAG4L tagged with Myc and His.
Yanliang CHEN ; Zhi ZHENG ; Jianlong WANG ; Xiaozhe ZHOU ; Yan LI ; Meng YANG ; Lihua HUANG ; Xiaowei XING
Chinese Journal of Biotechnology 2013;29(11):1654-1662
The aim of this study is to establish stable transfected cell lines which could produce SPAG4L protein labeled with Myc and His tags in vitro. The open reading frame (ORF) of human SPAG4L was amplified by PCR and the fragments were cloned into eukaryotic expression vector pcDNA3.1/myc-His(-)A. The recombined plasmids of pcDNA3.1/myc-His(-)A/SPAG4L were verified by sequencing and digestion with enzymes. Then, the recombined plasmids were introduced into HeLa cells and screened by G418. Western blotting was performed to detect the expression of SPAG4L and its tags in stable transfected cell lines. SPAG4L and its tags were expressed in the stable cell lines transfected with pcDNA3.1/myc-His(-)A/SPAG4L, but not in the control group. Further study showed that SPAG4L colocalized with the endoplasmic reticulum(ER) marker PDI by immunofluorescence. The stable transfected cell lines established in this study will provide a powerful tool for further studies such as co-immunoprecipitation and pull-down.
Carrier Proteins
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biosynthesis
;
genetics
;
Cloning, Molecular
;
Female
;
Genetic Vectors
;
genetics
;
HeLa Cells
;
Histidine
;
genetics
;
Humans
;
Male
;
Proto-Oncogene Proteins c-myc
;
genetics
;
Recombinant Fusion Proteins
;
biosynthesis
;
genetics
;
isolation & purification
;
Transfection

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