Objective: To characterize the expression of ST13 protein in human tissuesfor investigation of the function of colorectal cancer related gene ST13. Methods: ST13 ORF wascloned and over-expressed in E.coli. The recombi...Objective: To characterize the expression of ST13 protein in human tissuesfor investigation of the function of colorectal cancer related gene ST13. Methods: ST13 ORF wascloned and over-expressed in E.coli. The recombinant ST13 protein was purified by affinitychromatography. ST13 monoclonal antibodies were generated and affinity purified with the recombinantprotein. Immunoblot and immunohistochemical staining were employed to analyze ST13 proteinexpression in human tissues. Results: The expression and purification of the recombinant ST13protein were confirmed by SDS-PAGE. The protein yield reached about 2.5 mg/L of induced bacterialculture with a purity of 91.3%. Three strains of hybridoma were obtained with antibody titers from10~4 to 10~5 in ascites fluids and with high specificity for ST13 protein. Immunoblot showed thatthe apparent Mr of ST13 protein in SW480 cells and human tissues estimated by SDS-PAGE mobility wasapproximately 50 000, which was about 10 000 larger than the 41 324 calculated, but theglycosylation of the protein was excluded. Computer modeling revealed the protein to be ahydrophilic molecule. Immunohistochemical staining showed that ST13 protein was evenly distributedin cytoplasm and expressed in colon, stomach, liver, and other epithelial cells. Differences in thestaining intensity of the protein were observed between normal and cancer tissues as well as amongdifferent normal or carcinoma tissues. Conclusion: ST13 protein is a cytoplasmic molecule with anapparent Mr of 50 000. The protein is expressed in colorectal and other epithelial tissues. Theexpression level of the protein is down-regulated in colorectal cancer and varies among differentnormal and/or carcinoma tissues. Comparison of cDNA sequences and protein characteristics indicatesthat ST13 protein and hsp70-interacting protein (Hip) are same proteins, raising the possibilitythat ST13 protein is involved in the development of colorectal cancer through Hsp70 molecularchaperone machinery.展开更多
Cyclic AMP-binding protein was purified 30 fold from the mycelia of Ganoderma lucidum by the methods of ammonium sulfate precipitation, DEAE-cellulose, phospho-cellulose ion exchange chromatography and Sephacryl S-100...Cyclic AMP-binding protein was purified 30 fold from the mycelia of Ganoderma lucidum by the methods of ammonium sulfate precipitation, DEAE-cellulose, phospho-cellulose ion exchange chromatography and Sephacryl S-100 gel filtration. The molecular mass of the purified protein is 34.5 kDa and 17 kDa by Sephacryl S-100 gel filtration and SDS-ployacrylamide gel electrophoresis, respectively. From these results it is suggested that the protein has a homometric dimmer structure. The pI of the purified protein is pH 8.2 by native isoelectric focusing gel. The half-life of the protein activity in 10% glycerol at 4 ℃ is 7 d in crude extract, but its half-life is only 3 d under purifying conditions. The optimal conditions of the protein activity are at 1 ℃ and pH 7.5. Its activity is increased 6 times by 1 mmol/L Zn^(2+) and is slightly inhibited by cGMP, Cu^(2+) and Mn^(2+).展开更多
Stress-associated proteins(SAPs)are known as response factors to multiple abiotic and biotic stresses in plants.However,the potential physiological and molecular functions of SAPs remain largely unclear.Castor bean(Ri...Stress-associated proteins(SAPs)are known as response factors to multiple abiotic and biotic stresses in plants.However,the potential physiological and molecular functions of SAPs remain largely unclear.Castor bean(Ricinus communis L.)is one of the most economically valuable non-edible woody oilseed crops,able to be widely cultivated in marginal lands worldwide because of its broad adaptive capacity to soil and climate conditions.Whether SAPs in castor bean plays a key role in adapting diverse soil conditions and stresses remains unknown.In this study,we used the castor bean genome to identify and characterize nine castor bean SAP genes(RcSAP).Structural analysis showed that castor bean SAP gene structures and functional domain types vary greatly,differing in intron number,protein sequence,and functional domain type.Notably,the AN1-C2H2eC2H2 zinc finger domain within RcSAP9 has not been often observed in other plant families.High throughput RNA-seq data showed that castor bean SAP gene profiles varied among different tissues.In addition,castor bean SAP gene expression varied in response to different stresses,including salt,drought,heat,cold and ABA and MeJA,suggesting that the transcriptional regulation of castor bean SAP genes might operate independently of each other,and at least partially independent from ABA and MeJA signal pathways.Cis-element analyses for each castor bean SAP gene showed that no common cis-elements are shared across the nine castor bean SAP genes.Castor bean SAPs were localized to different regions of cells,including the cytoplasm,nucleus,and cytomembrane.This study provides a comprehensive profile of castor bean SAP genes that advances our understanding of their potential physiological and molecular functions in regulating growth and development and their responses to different abiotic stresses.展开更多
Wide hybridization is an effective approach for enhancing the resistance of bread wheat （Triticum aestivum L.） to biotic and abiotic stresses by introducing favorable alien genes （Sepsi et al., 2008）. Wheatgrass, ...Wide hybridization is an effective approach for enhancing the resistance of bread wheat （Triticum aestivum L.） to biotic and abiotic stresses by introducing favorable alien genes （Sepsi et al., 2008）. Wheatgrass, Thinopyrum intermedium （Host） Barkworth ＆ D.R. Dewey or Agropyron intermedium （Host） Beauvoir （2n = 42; genome formula JJjSjSstst）, is a perennial species in the tribe Triticeae and an important source of wheat improvement for biotic and abiotic stress resistance and quality-related traits, such as high grain protein concentration （Chen et al., 1998; 2001; 2003; Han et al., 2004; Li and Wang, 2009）. In addition, the ready crossing ability of wheatgrass with various Triticum species has made it popular in germ- plasm development.展开更多
This study presents an exploration on extending the action of therapeutic proteins by crystallization strategy without new molecular entities generation.Recombinant human interferon a-2b(rhIFN),a model protein drug in...This study presents an exploration on extending the action of therapeutic proteins by crystallization strategy without new molecular entities generation.Recombinant human interferon a-2b(rhIFN),a model protein drug in this case,was crystallized using a hanging drop vapor diffusion method.A novel chelating technique with metal ions was employed to promote crystals formation.The physico-chemical characterization of the protein crystals,including morphology,particle size,X-ray diffraction,circular dichroism and biological potency evaluations were performed.In addition,the in vitro release behavior of rhIFN from crystal lattice suggested an exciting possibility of protein crystals as a longacting formulation.The work described here demonstrates the possibility of spherical crystals of biomacromolecules for controllable delivery application of therapeutic proteins.展开更多
To analyze whether expressed amyloid precursor protein（APP） existed in hydrophilic（cytoplasmid） or hydrophobic（lipid bilayer） environment in E. coli and to obtain intact APP for study on its function, we investi...To analyze whether expressed amyloid precursor protein（APP） existed in hydrophilic（cytoplasmid） or hydrophobic（lipid bilayer） environment in E. coli and to obtain intact APP for study on its function, we investigated the expression characterization and preparation of the three intact isoforms APP770, APP751, and APP695 in E. coll. The results show that these expressed APPs existed both in hydrophilic cytoplasm region as inclusion bodies and hydrophobic membrane region as membrane-bound state in E. coll. APPs in inclusion bodies were purified on an NTA-Ni^2＋ agarose column after dissolving in the urea buffer and APPs in membrane-bound state were obtained by ultracentrifugation. The activity analysis indicates that APP770 and APP751 exhibited strong trypsin-inhibitory activity like the natural ones. These results indicate that E. coli cells can be used as host cells for the expression of human integral membrane protein like APP in either soluble or membrane-bound state unless the interest protein undergone post-translational modification is required.展开更多
This study objective was to express and characterize the catalytic domain of the human T cell protein tyrosine phosphatase（△TC-PTP） and to study immunohistochemically the expression of △TC-PTP in human non-small c...This study objective was to express and characterize the catalytic domain of the human T cell protein tyrosine phosphatase（△TC-PTP） and to study immunohistochemically the expression of △TC-PTP in human non-small cell lung cancers. △TC-PTP gene was PCR amplified with the cDNA of human TC-PTP as template, and cloned into the pT7 expression vector. The recombinant pT7-△TC-PTP was expressed in E. coli Rosetta （ DE3 ） host cells and puri- fied. The enzymatic characteristics of △TC-PTP including enzyme activity and kinetics assay were measured. The antiserum was prepared by immunizing rabbit with the purified recombinant △TC-PTP. Rabbit polyclonal antibody against △TC-PTP was purified by PVDF immobilized antigen affinity chromatography. Immunohistochemical staining of lung cancer tissues was performed with antibody against △TC-PTP protein. △TC-PTP gene was correctly cloned, expressed, and purified. The recombinant △TC-PTP had a highly catalytic activity of PTPase. Squamous cell lung carcinoma showed a significantly higher expression rate of △TC-PTP （76. 92%, 10/13 ） than adenocarcinoma （57.14%, 4/7） and normal lung tissue（20%, 1/5 ）. This study represents the first demonstration that △TC-PTP is highly expressed in human squamous cell lung carcinomas. In addition, this study provides an important basis for further studying the biological function of TC-PTP and its relationship with lung carcinomas and other diseases.展开更多
LEA5 gene was postulated related with both stress and hormone responses.In an attempt to find genes exclusively expressed during fruit ripening of Cara Cara navel orange,a novel cDNA clone encoding late embryogenesis-...LEA5 gene was postulated related with both stress and hormone responses.In an attempt to find genes exclusively expressed during fruit ripening of Cara Cara navel orange,a novel cDNA clone encoding late embryogenesis-abundant protein 5 like gene(CitLEA5-1)was obtained.It was 582 bp in length,containing 97 deduced amino acids.Compared with the stress-induced LEA5 from leaves of Citrus sinensis,CitLEA5-1 had a shorter 3′untranslated region(UTR).Semi-quantitative RT-PCR analysis revealed that CitLEA5-1 was transcriptional regulated during fruit ripening of Cara Cara navel orange.展开更多
Avian influenza, subtype H5N1, causes occasional but serious infections in humans and efforts to produce vaccines against this strain continue. Current influenza vaccines are prophylactic and utilize the two major ant...Avian influenza, subtype H5N1, causes occasional but serious infections in humans and efforts to produce vaccines against this strain continue. Current influenza vaccines are prophylactic and utilize the two major antigens, hemagglutinin and neuraminidase. Nucleocapsid protein (NP) is an attractive alternative antigen because it is highly conserved across all influenza strains, has been shown to increase the rate of viral clearance, and potential therapeutic vaccines would elicit cytotoxic T lymphocyte responses in an infected person. The NP antigen from H5N1 was characterized using a variety of physico-chemical methods to gain insights into both the biological and physical properties of the antigen which are important from a regulatory viewpoint when considering therapeutic vaccines. Results obtained to date show that NP is relatively unstable and indicate that the conformation of the H5N1 NP antigen is highly dependent upon purification procedure, buffer conditions, pH and the presence or absence of RNA. These factors will need to be clearly defined and taken into consideration when manufacturing and regulating NP vaccine preparations.展开更多
Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether ...Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce allergenicity.We here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic proteins.Detection techniques for characterizing changes in these properties of food allergens are summarized.Food processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new epitopes.Moreover,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food components.We provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.展开更多
The full-length cDNA encoding Larval serum protein 2 (LSp-2) in the onion maggot,Delia antiqua, was cloned and sequenced by rapid ampli?cation of cDNA ends methods. The result showed that the cDNA was 2203 bp long and...The full-length cDNA encoding Larval serum protein 2 (LSp-2) in the onion maggot,Delia antiqua, was cloned and sequenced by rapid ampli?cation of cDNA ends methods. The result showed that the cDNA was 2203 bp long and the open reading frame (ORF) of 2106 bp encoded 701 amino acid with a calculated molecular weight of 80.5 kDa and an isoelectric point of 5.87. The onion maggot LSp-2 shows highest homology (83%) to that ofCalliphora vicinaat amino acid level. Its signal peptides, domains and structures were predicted and analyzed by using bioinformatic methods. The amino acid sequence of LSP-2 suggests that it would be a typical hexamerin.展开更多
Objective:To construct a secretory eukaryotic expression vector of DSG2 fused with the Fc region of the human IgG,to validate its expression in 293T cells,and to purify the secretory protein with biological activity.M...Objective:To construct a secretory eukaryotic expression vector of DSG2 fused with the Fc region of the human IgG,to validate its expression in 293T cells,and to purify the secretory protein with biological activity.Methods:The DSG2 extracellular domain fragment gene(DSG2ex),was amplified by PCR,and was inserted into the eukaryotic expression plasmid pCMV3-IgG1 to construct the recombinant eukaryotic expression plasmid-pCMV3-DSG2ex-IgG1.The successfully constructed eukaryotic expression plasmid was transfected into 293T cells to express and secrete DSG2 extracellular domain protein.The targeted protein was purified from the cell culture supernatant by Protein A affinity chromatography and confirmed by Western Blotting and ELISA.Results:The pCMV3-DSG2ex-IgG1 eukaryotic expression plasmid was successfully constructed.The highest protein expression level was obtained with 293T cells after 96 h of transfection.The relative molecular mass of the purified product was between 100 and 130 kDa was estimated by SDS-PAGE,which was consistent with the expectation.The yield of the purified protein reached 0.8 mg/ml with a purity over 90%.The purified DSG2 extracellular domain protein with IgG1 tag was recognized by IgG monoclonal antibodies by Western blotting.Moreover,the ELISA results showed that the prepared DSG2 extracellular domain protein had significant binding activity to human type 55 adenovirus Fiber Knob protein(HAdV-55).Conclusion:A simple and efficient method for eukaryotic expression and purification of human soluble DSG2 extracellular domain protein was successfully established,and biologically active DSG2 extracellular domain protein was purified,which laid the foundation for the later study of its protein function and anti-adenovirus drugs.展开更多
CAP,an adenylyl cyclase-associated protein,is predicted to be involved in cytoskeletal organization and signal transduction.Recently,we found that CAP may play an important role in fuzz-like fiber cell initiation in c...CAP,an adenylyl cyclase-associated protein,is predicted to be involved in cytoskeletal organization and signal transduction.Recently,we found that CAP may play an important role in fuzz-like fiber cell initiation in cotton.For the further research,we isolated two CAP homologues from wild展开更多
Potyviruses are major constraints to grain legume production by causing significant yield losses. Potyviruses infecting Bambara groundnut (Vigna subterranea) were investigated in Burkina Faso. Leaf samples collected f...Potyviruses are major constraints to grain legume production by causing significant yield losses. Potyviruses infecting Bambara groundnut (Vigna subterranea) were investigated in Burkina Faso. Leaf samples collected from three agroclimatic zones were subjected to RT-PCR and sequence analyses. Of a total of 135 samples, 36 (26.67%) were detected positive in RT-PCR tests using potyvirus universal primers. Analysis of full coat protein (cp) sequences from 24 isolates revealed the occurrence of three groups of Bambara groundnut-infecting potyviruses. Virus isolates in group 1 shared 94.5% - 100% nucleotide (nt) identity with CABMV whereas those in group 2 and group 3 were distantly related Bean common necrosis virus (BCMNV) and Passiflora virus Ugandan which were their respective closest potyviruses. Group 2 shared 77.1% nt and 78.8% - 79.9% aa identity with BCMNV and group 3 shared 77.3% - 78.3% nt and 80.7% - 81.5% aa identity with Passiflora virus Ugandan. All three groups were confirmed by phylogenetic analyses. Taking into account potyvirus demarcation criteria, group 1 isolates belonged to CABMV species. Group 2 and group 3 were assigned to a potentially new potyviruses species and designated Bambara groundnut potyvirus 1 (BGPV1) and Bambara groundnut potyvirus 2 (BGPV2).展开更多
Crystallization of proteins is a very delicate process, which is influenced by many known and unknown factors. Of tested factors, many factors are exclusively related to individual amino-acid characters such as molecu...Crystallization of proteins is a very delicate process, which is influenced by many known and unknown factors. Of tested factors, many factors are exclusively related to individual amino-acid characters such as molecular weight or protein characters such as protein length. It is considered necessary to test factors that combine both individual amino-acid characters and protein characters with respect to success rate of crystallization. In this study, two combined characters characterizing individual amino-acid character and protein character, amino acid distribution probability and future composition, were used to correlate the success rate of crystallization of proteins from Lactobacillus via modeling. The results obtained from logistic regression and neural network were compared against the results obtained from each of 533 individual amino-acid characters. This study demonstrated that the combined characters are involved in crystallization process and should be taken into account for predicting the success rate of crystallization process.展开更多
Gelatin is a product obtained through partial hydrolysis and thermal denaturation of collagen,belonging to natural biopeptides.With irreplaceable biological functions in the field of biomedical science and tissue engi...Gelatin is a product obtained through partial hydrolysis and thermal denaturation of collagen,belonging to natural biopeptides.With irreplaceable biological functions in the field of biomedical science and tissue engineering,it has been widely applied.The amino acid sequence of recombinant human-like gelatin was constructed through a newly designed hexamer composed of six protein monomer sequences in series,with the minimum repeating unit being the characteristic Gly-X-Y sequence found in type III human collagenα1 chain.The nucleotide sequence was subsequently inserted into the genome of Pichia pastoris to enable soluble secretion expression of recombinant gelatin.At the shake flask fermentation level,the yield of recombinant gelatin is up to 0.057 g/L,and its purity can rise up to 95%through affinity purification.It was confirmed in the molecular weight determination and amino acid analysis that the amino acid composition of the obtained recombinant gelatin is identical to that of the theoretically designed.Furthermore,scanning electron microscopy revealed that the freeze-dried recombinant gelatin hydrogel exhibited a porous structure.After culturing cells continuously within these gelatin microspheres for two days followed by fluorescence staining and observation through confocal laser scanning microscopy,it was observed that cells clustered together within the gelatin matrix,exhibiting three-dimensional growth characteristics while maintaining good viability.This research presents promising prospects for developing recombinant gelatin as a biomedical material.展开更多
HCLS1-associated protein X-1(HAX1)is a multifunctional mitochondrial protein involved in the regulation of apoptosis,a crucial process of programmed cell death,and mRNA processing.Despite its significance,limited stru...HCLS1-associated protein X-1(HAX1)is a multifunctional mitochondrial protein involved in the regulation of apoptosis,a crucial process of programmed cell death,and mRNA processing.Despite its significance,limited structural data is available for HAX1,hindering a comprehensive understanding of its biological function.Notably,the caseinolytic mitochondrial matrix peptidase chaperone subunit B(CLPB)has been identified as an interacting partner of HAX1,yet the biophysical properties and binding affinity governing their interaction remain poorly defined.In this study,we present a thorough biophysical characterization of full-length human HAX1 and CLPB,accomplished through recombinant expression and purification.By employing size exclusion chromatography,dynamic light scattering,and circular dichroism spectroscopy,we successfully established their biophysical properties,revealing contrasting structural features,with CLPB displaying a-helical content and HAX1 exhibiting a disordered nature.Moreover,we employed solutionstate nuclear magnetic resonance(NMR)spectroscopy to probe their binding affinity.Our findings demonstrate the formation of stable multimeric complexes between HAX1 and CLPB,and we quantified a dissociation constant in the low range of micro-molar for their high affinity interaction.These results lay the foundation for further in-depth investigations into the dynamics and energetics governing the HAX1-CLPB interaction,ultimately contributing to a comprehensive understanding of their functional mechanisms.展开更多
AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical ...AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPI-YA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using χ2 test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation.展开更多
Sodium implanted titanium films with different ion doses were characterized to correlate their ion implantation parameters. Native titanium films and ion implanted titanium films were characterized with combined techn...Sodium implanted titanium films with different ion doses were characterized to correlate their ion implantation parameters. Native titanium films and ion implanted titanium films were characterized with combined techniques of X-ray photoelectron spectroscopy （XPS）, atomic force microscopy （AFM）, and light microscopy （LM）. The surface presented increased sodium concentration on treated titanium films with ion dose increasing, except for the group with the highest ion dose of 4×10^17ions/cm^2. XPS depth profiling displayed that sodium entered titanium film around 25-50nm depth depending on its implantation ion dose. AFM characterization showed that sodium ion implantation treatment changed the surface morphology from a relatively smooth titanium film to rough surfaces corresponding to different implantation doses. After sodium implantation, implanted titanium films presented big particles with island structure morphology. The surface morphology and particle growth displayed the corresponding trend. Fibrinogen adsorption on these titanium films was performed to correlate with the surface properties of treated titanium films. The results show that protein adsorption on ion-implanted samples with dose of 2×10^17 and 4×10^17 are statistically higher （p 〈0.01） than samples treated with dose of 5×10^16 and 1×10^17, as well as the control samples.展开更多
文摘Objective: To characterize the expression of ST13 protein in human tissuesfor investigation of the function of colorectal cancer related gene ST13. Methods: ST13 ORF wascloned and over-expressed in E.coli. The recombinant ST13 protein was purified by affinitychromatography. ST13 monoclonal antibodies were generated and affinity purified with the recombinantprotein. Immunoblot and immunohistochemical staining were employed to analyze ST13 proteinexpression in human tissues. Results: The expression and purification of the recombinant ST13protein were confirmed by SDS-PAGE. The protein yield reached about 2.5 mg/L of induced bacterialculture with a purity of 91.3%. Three strains of hybridoma were obtained with antibody titers from10~4 to 10~5 in ascites fluids and with high specificity for ST13 protein. Immunoblot showed thatthe apparent Mr of ST13 protein in SW480 cells and human tissues estimated by SDS-PAGE mobility wasapproximately 50 000, which was about 10 000 larger than the 41 324 calculated, but theglycosylation of the protein was excluded. Computer modeling revealed the protein to be ahydrophilic molecule. Immunohistochemical staining showed that ST13 protein was evenly distributedin cytoplasm and expressed in colon, stomach, liver, and other epithelial cells. Differences in thestaining intensity of the protein were observed between normal and cancer tissues as well as amongdifferent normal or carcinoma tissues. Conclusion: ST13 protein is a cytoplasmic molecule with anapparent Mr of 50 000. The protein is expressed in colorectal and other epithelial tissues. Theexpression level of the protein is down-regulated in colorectal cancer and varies among differentnormal and/or carcinoma tissues. Comparison of cDNA sequences and protein characteristics indicatesthat ST13 protein and hsp70-interacting protein (Hip) are same proteins, raising the possibilitythat ST13 protein is involved in the development of colorectal cancer through Hsp70 molecularchaperone machinery.
基金Supported by Korea Science and Engineering Foundation(KOSEF)
文摘Cyclic AMP-binding protein was purified 30 fold from the mycelia of Ganoderma lucidum by the methods of ammonium sulfate precipitation, DEAE-cellulose, phospho-cellulose ion exchange chromatography and Sephacryl S-100 gel filtration. The molecular mass of the purified protein is 34.5 kDa and 17 kDa by Sephacryl S-100 gel filtration and SDS-ployacrylamide gel electrophoresis, respectively. From these results it is suggested that the protein has a homometric dimmer structure. The pI of the purified protein is pH 8.2 by native isoelectric focusing gel. The half-life of the protein activity in 10% glycerol at 4 ℃ is 7 d in crude extract, but its half-life is only 3 d under purifying conditions. The optimal conditions of the protein activity are at 1 ℃ and pH 7.5. Its activity is increased 6 times by 1 mmol/L Zn^(2+) and is slightly inhibited by cGMP, Cu^(2+) and Mn^(2+).
基金This research was funded by National Natural Science Foundation of China(31661143002,31771839,31701123and 31501034)Yunnan Applied Basic Research Projects(2016FB060 and 2016FB040).
文摘Stress-associated proteins(SAPs)are known as response factors to multiple abiotic and biotic stresses in plants.However,the potential physiological and molecular functions of SAPs remain largely unclear.Castor bean(Ricinus communis L.)is one of the most economically valuable non-edible woody oilseed crops,able to be widely cultivated in marginal lands worldwide because of its broad adaptive capacity to soil and climate conditions.Whether SAPs in castor bean plays a key role in adapting diverse soil conditions and stresses remains unknown.In this study,we used the castor bean genome to identify and characterize nine castor bean SAP genes(RcSAP).Structural analysis showed that castor bean SAP gene structures and functional domain types vary greatly,differing in intron number,protein sequence,and functional domain type.Notably,the AN1-C2H2eC2H2 zinc finger domain within RcSAP9 has not been often observed in other plant families.High throughput RNA-seq data showed that castor bean SAP gene profiles varied among different tissues.In addition,castor bean SAP gene expression varied in response to different stresses,including salt,drought,heat,cold and ABA and MeJA,suggesting that the transcriptional regulation of castor bean SAP genes might operate independently of each other,and at least partially independent from ABA and MeJA signal pathways.Cis-element analyses for each castor bean SAP gene showed that no common cis-elements are shared across the nine castor bean SAP genes.Castor bean SAPs were localized to different regions of cells,including the cytoplasm,nucleus,and cytomembrane.This study provides a comprehensive profile of castor bean SAP genes that advances our understanding of their potential physiological and molecular functions in regulating growth and development and their responses to different abiotic stresses.
基金supported by the Provincial Prize Fund for Distinguished Young and Middle-aged Scientists of Shandong Province(No.BS2011SW053)State Key Laboratory of Plant Cell and Chromosome Engineering(No.PCCE-KF-2014-01)State Key Laboratory of Crop Biology(No.2015KF06)
文摘Wide hybridization is an effective approach for enhancing the resistance of bread wheat （Triticum aestivum L.） to biotic and abiotic stresses by introducing favorable alien genes （Sepsi et al., 2008）. Wheatgrass, Thinopyrum intermedium （Host） Barkworth ＆ D.R. Dewey or Agropyron intermedium （Host） Beauvoir （2n = 42; genome formula JJjSjSstst）, is a perennial species in the tribe Triticeae and an important source of wheat improvement for biotic and abiotic stress resistance and quality-related traits, such as high grain protein concentration （Chen et al., 1998; 2001; 2003; Han et al., 2004; Li and Wang, 2009）. In addition, the ready crossing ability of wheatgrass with various Triticum species has made it popular in germ- plasm development.
基金The authors wish to thank the National Natural Science Foundation of China (No. 81072604/31170967) for financial support.
文摘This study presents an exploration on extending the action of therapeutic proteins by crystallization strategy without new molecular entities generation.Recombinant human interferon a-2b(rhIFN),a model protein drug in this case,was crystallized using a hanging drop vapor diffusion method.A novel chelating technique with metal ions was employed to promote crystals formation.The physico-chemical characterization of the protein crystals,including morphology,particle size,X-ray diffraction,circular dichroism and biological potency evaluations were performed.In addition,the in vitro release behavior of rhIFN from crystal lattice suggested an exciting possibility of protein crystals as a longacting formulation.The work described here demonstrates the possibility of spherical crystals of biomacromolecules for controllable delivery application of therapeutic proteins.
基金Supported by the Fund from Science & Technology Department of Jilin Province, China(Nos.20060725, 20070926-02).
文摘To analyze whether expressed amyloid precursor protein（APP） existed in hydrophilic（cytoplasmid） or hydrophobic（lipid bilayer） environment in E. coli and to obtain intact APP for study on its function, we investigated the expression characterization and preparation of the three intact isoforms APP770, APP751, and APP695 in E. coll. The results show that these expressed APPs existed both in hydrophilic cytoplasm region as inclusion bodies and hydrophobic membrane region as membrane-bound state in E. coll. APPs in inclusion bodies were purified on an NTA-Ni^2＋ agarose column after dissolving in the urea buffer and APPs in membrane-bound state were obtained by ultracentrifugation. The activity analysis indicates that APP770 and APP751 exhibited strong trypsin-inhibitory activity like the natural ones. These results indicate that E. coli cells can be used as host cells for the expression of human integral membrane protein like APP in either soluble or membrane-bound state unless the interest protein undergone post-translational modification is required.
基金Supported by the Fund of Science and Technology Department of Jilin Province(No20060563)in part by the Fund of Scienceand Technology Department of Jilin Province(No200505120) the Bureau of Science and Technology of Changchun City(No06GG110)
文摘This study objective was to express and characterize the catalytic domain of the human T cell protein tyrosine phosphatase（△TC-PTP） and to study immunohistochemically the expression of △TC-PTP in human non-small cell lung cancers. △TC-PTP gene was PCR amplified with the cDNA of human TC-PTP as template, and cloned into the pT7 expression vector. The recombinant pT7-△TC-PTP was expressed in E. coli Rosetta （ DE3 ） host cells and puri- fied. The enzymatic characteristics of △TC-PTP including enzyme activity and kinetics assay were measured. The antiserum was prepared by immunizing rabbit with the purified recombinant △TC-PTP. Rabbit polyclonal antibody against △TC-PTP was purified by PVDF immobilized antigen affinity chromatography. Immunohistochemical staining of lung cancer tissues was performed with antibody against △TC-PTP protein. △TC-PTP gene was correctly cloned, expressed, and purified. The recombinant △TC-PTP had a highly catalytic activity of PTPase. Squamous cell lung carcinoma showed a significantly higher expression rate of △TC-PTP （76. 92%, 10/13 ） than adenocarcinoma （57.14%, 4/7） and normal lung tissue（20%, 1/5 ）. This study represents the first demonstration that △TC-PTP is highly expressed in human squamous cell lung carcinomas. In addition, this study provides an important basis for further studying the biological function of TC-PTP and its relationship with lung carcinomas and other diseases.
基金the National Natural Science Foundation of China(30300241,30471201).
文摘LEA5 gene was postulated related with both stress and hormone responses.In an attempt to find genes exclusively expressed during fruit ripening of Cara Cara navel orange,a novel cDNA clone encoding late embryogenesis-abundant protein 5 like gene(CitLEA5-1)was obtained.It was 582 bp in length,containing 97 deduced amino acids.Compared with the stress-induced LEA5 from leaves of Citrus sinensis,CitLEA5-1 had a shorter 3′untranslated region(UTR).Semi-quantitative RT-PCR analysis revealed that CitLEA5-1 was transcriptional regulated during fruit ripening of Cara Cara navel orange.
文摘Avian influenza, subtype H5N1, causes occasional but serious infections in humans and efforts to produce vaccines against this strain continue. Current influenza vaccines are prophylactic and utilize the two major antigens, hemagglutinin and neuraminidase. Nucleocapsid protein (NP) is an attractive alternative antigen because it is highly conserved across all influenza strains, has been shown to increase the rate of viral clearance, and potential therapeutic vaccines would elicit cytotoxic T lymphocyte responses in an infected person. The NP antigen from H5N1 was characterized using a variety of physico-chemical methods to gain insights into both the biological and physical properties of the antigen which are important from a regulatory viewpoint when considering therapeutic vaccines. Results obtained to date show that NP is relatively unstable and indicate that the conformation of the H5N1 NP antigen is highly dependent upon purification procedure, buffer conditions, pH and the presence or absence of RNA. These factors will need to be clearly defined and taken into consideration when manufacturing and regulating NP vaccine preparations.
基金supported by the National Natural Science Foundation of China (32102605)the Agricultural Science and Technology Innovation Program under Grant (CAAS-ASTIP-2020IAR)the Earmarked Fund for CARS (CARS-44)。
文摘Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce allergenicity.We here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic proteins.Detection techniques for characterizing changes in these properties of food allergens are summarized.Food processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new epitopes.Moreover,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food components.We provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.
文摘The full-length cDNA encoding Larval serum protein 2 (LSp-2) in the onion maggot,Delia antiqua, was cloned and sequenced by rapid ampli?cation of cDNA ends methods. The result showed that the cDNA was 2203 bp long and the open reading frame (ORF) of 2106 bp encoded 701 amino acid with a calculated molecular weight of 80.5 kDa and an isoelectric point of 5.87. The onion maggot LSp-2 shows highest homology (83%) to that ofCalliphora vicinaat amino acid level. Its signal peptides, domains and structures were predicted and analyzed by using bioinformatic methods. The amino acid sequence of LSP-2 suggests that it would be a typical hexamerin.
基金Nanjing Science and Technology Plan Project(No.ZX20200009)Jiangsu Province Postgraduate Research and Practice Innovation Program(No.SJCX22-0895)。
文摘Objective:To construct a secretory eukaryotic expression vector of DSG2 fused with the Fc region of the human IgG,to validate its expression in 293T cells,and to purify the secretory protein with biological activity.Methods:The DSG2 extracellular domain fragment gene(DSG2ex),was amplified by PCR,and was inserted into the eukaryotic expression plasmid pCMV3-IgG1 to construct the recombinant eukaryotic expression plasmid-pCMV3-DSG2ex-IgG1.The successfully constructed eukaryotic expression plasmid was transfected into 293T cells to express and secrete DSG2 extracellular domain protein.The targeted protein was purified from the cell culture supernatant by Protein A affinity chromatography and confirmed by Western Blotting and ELISA.Results:The pCMV3-DSG2ex-IgG1 eukaryotic expression plasmid was successfully constructed.The highest protein expression level was obtained with 293T cells after 96 h of transfection.The relative molecular mass of the purified product was between 100 and 130 kDa was estimated by SDS-PAGE,which was consistent with the expectation.The yield of the purified protein reached 0.8 mg/ml with a purity over 90%.The purified DSG2 extracellular domain protein with IgG1 tag was recognized by IgG monoclonal antibodies by Western blotting.Moreover,the ELISA results showed that the prepared DSG2 extracellular domain protein had significant binding activity to human type 55 adenovirus Fiber Knob protein(HAdV-55).Conclusion:A simple and efficient method for eukaryotic expression and purification of human soluble DSG2 extracellular domain protein was successfully established,and biologically active DSG2 extracellular domain protein was purified,which laid the foundation for the later study of its protein function and anti-adenovirus drugs.
文摘CAP,an adenylyl cyclase-associated protein,is predicted to be involved in cytoskeletal organization and signal transduction.Recently,we found that CAP may play an important role in fuzz-like fiber cell initiation in cotton.For the further research,we isolated two CAP homologues from wild
文摘Potyviruses are major constraints to grain legume production by causing significant yield losses. Potyviruses infecting Bambara groundnut (Vigna subterranea) were investigated in Burkina Faso. Leaf samples collected from three agroclimatic zones were subjected to RT-PCR and sequence analyses. Of a total of 135 samples, 36 (26.67%) were detected positive in RT-PCR tests using potyvirus universal primers. Analysis of full coat protein (cp) sequences from 24 isolates revealed the occurrence of three groups of Bambara groundnut-infecting potyviruses. Virus isolates in group 1 shared 94.5% - 100% nucleotide (nt) identity with CABMV whereas those in group 2 and group 3 were distantly related Bean common necrosis virus (BCMNV) and Passiflora virus Ugandan which were their respective closest potyviruses. Group 2 shared 77.1% nt and 78.8% - 79.9% aa identity with BCMNV and group 3 shared 77.3% - 78.3% nt and 80.7% - 81.5% aa identity with Passiflora virus Ugandan. All three groups were confirmed by phylogenetic analyses. Taking into account potyvirus demarcation criteria, group 1 isolates belonged to CABMV species. Group 2 and group 3 were assigned to a potentially new potyviruses species and designated Bambara groundnut potyvirus 1 (BGPV1) and Bambara groundnut potyvirus 2 (BGPV2).
文摘Crystallization of proteins is a very delicate process, which is influenced by many known and unknown factors. Of tested factors, many factors are exclusively related to individual amino-acid characters such as molecular weight or protein characters such as protein length. It is considered necessary to test factors that combine both individual amino-acid characters and protein characters with respect to success rate of crystallization. In this study, two combined characters characterizing individual amino-acid character and protein character, amino acid distribution probability and future composition, were used to correlate the success rate of crystallization of proteins from Lactobacillus via modeling. The results obtained from logistic regression and neural network were compared against the results obtained from each of 533 individual amino-acid characters. This study demonstrated that the combined characters are involved in crystallization process and should be taken into account for predicting the success rate of crystallization process.
基金financially supported by the Anhui Provincial Natural Science Foundation(No.2022AH052316,GXXT-2022-002,KJ2021A1273).
文摘Gelatin is a product obtained through partial hydrolysis and thermal denaturation of collagen,belonging to natural biopeptides.With irreplaceable biological functions in the field of biomedical science and tissue engineering,it has been widely applied.The amino acid sequence of recombinant human-like gelatin was constructed through a newly designed hexamer composed of six protein monomer sequences in series,with the minimum repeating unit being the characteristic Gly-X-Y sequence found in type III human collagenα1 chain.The nucleotide sequence was subsequently inserted into the genome of Pichia pastoris to enable soluble secretion expression of recombinant gelatin.At the shake flask fermentation level,the yield of recombinant gelatin is up to 0.057 g/L,and its purity can rise up to 95%through affinity purification.It was confirmed in the molecular weight determination and amino acid analysis that the amino acid composition of the obtained recombinant gelatin is identical to that of the theoretically designed.Furthermore,scanning electron microscopy revealed that the freeze-dried recombinant gelatin hydrogel exhibited a porous structure.After culturing cells continuously within these gelatin microspheres for two days followed by fluorescence staining and observation through confocal laser scanning microscopy,it was observed that cells clustered together within the gelatin matrix,exhibiting three-dimensional growth characteristics while maintaining good viability.This research presents promising prospects for developing recombinant gelatin as a biomedical material.
基金supported by grants from the Special Foundation of President of the Chinese Academy of Sciences(Grant No.,YZJJ2020QN27,YZJJ2021QN33)Anhui Provincial Natural Science Foundation(Grant No.,2108085MC79).
文摘HCLS1-associated protein X-1(HAX1)is a multifunctional mitochondrial protein involved in the regulation of apoptosis,a crucial process of programmed cell death,and mRNA processing.Despite its significance,limited structural data is available for HAX1,hindering a comprehensive understanding of its biological function.Notably,the caseinolytic mitochondrial matrix peptidase chaperone subunit B(CLPB)has been identified as an interacting partner of HAX1,yet the biophysical properties and binding affinity governing their interaction remain poorly defined.In this study,we present a thorough biophysical characterization of full-length human HAX1 and CLPB,accomplished through recombinant expression and purification.By employing size exclusion chromatography,dynamic light scattering,and circular dichroism spectroscopy,we successfully established their biophysical properties,revealing contrasting structural features,with CLPB displaying a-helical content and HAX1 exhibiting a disordered nature.Moreover,we employed solutionstate nuclear magnetic resonance(NMR)spectroscopy to probe their binding affinity.Our findings demonstrate the formation of stable multimeric complexes between HAX1 and CLPB,and we quantified a dissociation constant in the low range of micro-molar for their high affinity interaction.These results lay the foundation for further in-depth investigations into the dynamics and energetics governing the HAX1-CLPB interaction,ultimately contributing to a comprehensive understanding of their functional mechanisms.
基金Supported by Sciences Faculty,Los Andes University,Bogotá,Colombia and National Cancer Institute,Bogotá,Colombia,Grant No.41030310-28 (to Bravo MM)
文摘AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPI-YA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using χ2 test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation.
文摘Sodium implanted titanium films with different ion doses were characterized to correlate their ion implantation parameters. Native titanium films and ion implanted titanium films were characterized with combined techniques of X-ray photoelectron spectroscopy （XPS）, atomic force microscopy （AFM）, and light microscopy （LM）. The surface presented increased sodium concentration on treated titanium films with ion dose increasing, except for the group with the highest ion dose of 4×10^17ions/cm^2. XPS depth profiling displayed that sodium entered titanium film around 25-50nm depth depending on its implantation ion dose. AFM characterization showed that sodium ion implantation treatment changed the surface morphology from a relatively smooth titanium film to rough surfaces corresponding to different implantation doses. After sodium implantation, implanted titanium films presented big particles with island structure morphology. The surface morphology and particle growth displayed the corresponding trend. Fibrinogen adsorption on these titanium films was performed to correlate with the surface properties of treated titanium films. The results show that protein adsorption on ion-implanted samples with dose of 2×10^17 and 4×10^17 are statistically higher （p 〈0.01） than samples treated with dose of 5×10^16 and 1×10^17, as well as the control samples.
