Brazil is the center of diversity and dispersion of species of the genus Passiflora.Two species of passion fruit Passiflora tenuifila BRS VT(passiflora garlic)and another of Passiflora setacea BRS PC were used in this...Brazil is the center of diversity and dispersion of species of the genus Passiflora.Two species of passion fruit Passiflora tenuifila BRS VT(passiflora garlic)and another of Passiflora setacea BRS PC were used in this study.The plants were grown on the Embrapa Cerrados experimental farm.The fruits were washed,minimally cut and their constituents separated.Both species differed in the proportion of wet mass between husk,seed,and pulp.As expected,both species had a higher proportion of husks and seeds and a lower amount of pulp.A semi-purification procedure for the proteins present in the seeds and husks was described and the molecular aspects were analyzed by polyacrylamide gel electrophoresis(SDS-PAGE).The quantification of soluble proteins was performed using the Bradford method.The analysis of the soluble protein extracted from the seeds and husks showed that these values are up to 70 times higher for the seeds of P.tenuifila and 28.5 times for P.setacea,in the husks.It was verified that both species present a similar protein profile,observed by the intense and diverse bands found in the polyacrylamide gel,mainly in the range of 32 to 19 kDa.This work opens up an unexplored field of tracking bioactive proteins and/or peptides including forms of nanostructure systems that protect other bioactive molecules.The objective of this work was to present an analytical procedure to semi-purify seed proteins of two Passiflora species and use electrophoresis as an analysis tool for further screening of their protein profiles and selection of a molecular marker to differentiate them.展开更多
The regulation of protein stability is a fundamental issue for biophysical processes,but there has not previously been a convenient and unbiased method of identifying regulators of protein stability.However,as reporte...The regulation of protein stability is a fundamental issue for biophysical processes,but there has not previously been a convenient and unbiased method of identifying regulators of protein stability.However,as reported in the article entitled "A genome-scale CRISPR-Cas9 screening method for protein stability reveals novel regulators of Cdc25 A," recently published in Cell Discovery,our team developed a protein stability regulators screening assay(Pro-SRSA) by combining the whole-genome clustered regularly interspaced short palindromic repeats Cas9(CRISPR-Cas9) library with a dual-fluorescence-based protein stability reporter and high-throughput sequencing to screen for regulators of protein stability.Based on our findings,we are confident that this efficient and unbiased screening method at the genome scale will be used by researchers worldwide to identify regulators of protein stability.展开更多
The present study screened a human fetal brain cDNA library to find the proteins that interact with mutant superoxide dismutase 1 (SOD1) using a yeast two-hybrid system. Using BLAST software, 15 real proteins which ...The present study screened a human fetal brain cDNA library to find the proteins that interact with mutant superoxide dismutase 1 (SOD1) using a yeast two-hybrid system. Using BLAST software, 15 real proteins which interacted with mutant SOD1 were obtained, including 8 known proteins (protein tyrosine-phosphatase non-receptor type 2, TBCl D4, protein kinase family, splicing factor, arginine/serine-rich 2, SRC protein tyrosine kinase Fyn, β-sarcoglycan; glycine receptor a2, microtubule associated protein/microtubule affinity-regulating kinase 1, ferritin H chain), and 7 unknown proteins. Results demonstrated interaction of mutant SOD1 with microtubule associated protein/microtubule affinity-regulating kinase 1 and β-sarcoglycan.展开更多
A Flp/FRT EMS mutagenesis screen was conducted in the eye of Drosophila melanogaster on chromosome 2R to identify negative regulators of cell growth and cell division. In addition to the EMS mutation in the mosaic eye...A Flp/FRT EMS mutagenesis screen was conducted in the eye of Drosophila melanogaster on chromosome 2R to identify negative regulators of cell growth and cell division. In addition to the EMS mutation in the mosaic eye, an ark loss of function allele (ark<sup>82</sup>) was utilized to block apoptosis in the homozygous mutant cells, setting up a screen for conditional regulators of cell growth and cell division. In the present study, we focus on the characterization and mapping of one mutant that resulted from this screen, Cruella (cru). A cross between flies with the flippase enzyme directed to the developing eye and flies with the mutations cru, ark<sup>82</sup>, revealed an unusual phenotype that resulted in the homozygous mutant tissue appearing black, in contrast to the expected red. To map the location of this mutation, complementation tests against the Bloomington deficiency kit were conducted. Cru failed to complement previously characterized alleles of capping protein α (cpa). Thus, cpa<sup>cru</sup> is a novel allele of cpa and displays phenotypes similar to previously characterized alleles such as cpa 107E, cpa 69E, and cpa<sup>scrd</sup> . The human homolog, Cap Z, is conserved in humans and serves a similar role in act in filament regulation.展开更多
BRAF has been recognized as a promising target for cancer therapy. A number of crystal structures have been published. Molecular docking is one of the most effective techniques in the field of computer-aided drug des...BRAF has been recognized as a promising target for cancer therapy. A number of crystal structures have been published. Molecular docking is one of the most effective techniques in the field of computer-aided drug design(CADD). Appropriate protein conformation and docking method are essential for the successful virtual screening experiments. One approach considering protein flexibility and multiple docking methods was proposed in this study. Six DFG-in/αC-helix-out crystal structures of BRAF, three docking programs(Glide, GOLD and Ligand Fit) and 12 scoring functions were applied for the best combination by judging from the results of pose prediction and retrospective virtual screening(VS). The most accurate results(mean RMSD of about 0.6 A) of pose prediction were obtained with two complex structures(PDB: 3 C4 C and 3 SKC) using Glide SP. From the retrospective VS, the most active compounds were identified by using the complex structure of 3 SKC, indicated by a ROC/AUC score of 0.998 and an EF of 20.6 at 5% of the database screen with Glide-SP. On the whole, PDB 3 SKC could achieve a higher rate of correct reproduction, a better enrichment and more diverse compounds. A comparison of 3 SKC and the other X-ray crystal structures led to a rationale for the docking results. PDB 3 SKC could achieve a broad range of sulfonamide substitutions through an expanded hydrophobic pocket formed by a further shift of the αC-helix. Our study emphasized the necessity and significance of protein flexibility and scoring functions in both ligand docking and virtual screening.展开更多
Objective To screen the transient and stable cell lines with high production of Nectin-like 4(Necl-4)protein.Methods First,c DNA sequences encoding the extracellular domain of Necls were cloned into the modified vecto...Objective To screen the transient and stable cell lines with high production of Nectin-like 4(Necl-4)protein.Methods First,c DNA sequences encoding the extracellular domain of Necls were cloned into the modified vector p APtag at the N terminus of alkaline phosphatase(AP)for fusion expression.Next,293ET cells stably expressed Necls-AP fusion protein and secreted it into the culture medium which were detected by the AP activity assay and Western blot analysis.Then,by adding N-glycosylation processing inhibitor kifunensine into the medium,complex glycan was inhibited to generate.The residual glycan of purified protein was removed by endoglycosidase H.Finally,AP protein was removed by using human rhinovirus protease and size exclusion chromatography.The concentration of purified Necl-4 protein was monitored by measuring the absorbance at280 nm and analyzed by SDS-PAGE.Results The transient and stable cell lines with high production of Necl-4 protein were screened by the color reaction with the AP-tag in the recombinant vector.The soluble and active form of purified Necl-4 protein was obtained after deglycosylation of native N-glycan protein with an expression level of 4 mg/L culture and purity of 95%.Conclusions By using modified AP mammalian protein expression system,we can easily screen the high productive stable cell lines by using AP activity assay.By adding mannosidase inhibitor kifunensine into the medium and cutting purified protein by using endoglycosidase H,we can obtain deglycosylated Necl-4 protein in milligram quantities.Our method might throw a light on the expression and purification of glycoprotein for structural and functional studies.展开更多
Recently, a novel green fluorescent protein eYGFPuv has been identified in the marine organism Chiridius poppei which displays high fluorescence intensity and can be visible by eyes in dark. Although strong green fluo...Recently, a novel green fluorescent protein eYGFPuv has been identified in the marine organism Chiridius poppei which displays high fluorescence intensity and can be visible by eyes in dark. Although strong green fluorescence was achieved in transgenic petunia, 3 expression cassettes (about 8 kb) complicate its application. In this study, to confirm whether 1 expression cassette could be used as a transgenic marker in prokaryotes and eukaryotes, eYGFPuv was cloned into prokaryotic expression vector pET28α-eYGFPuv- His and plant binary expression vector 35S::eYGFPuv. Compared to EGFP, eYGFPuv protein exhibited stronger dazzling green fluorescence in E. coli under excited light at 365 nm and maintains steadily over a long period of time without degradation. When transiently expressed in tobacco leaves, eYGFPuv protein displayed strong green fluorescence. Moreover, the fluorescence of eYGFPuv protein also could be directly observed in living plant, and thus can be used easily as a marker to screen transformed lines in transgenic research. Overall, compared to previous studies on eYGFPuv tandem repeats, our data confirmed that single eYGFPuv sequence still possesses high fluorescence intensity and quenching resistance. Furthermore, because of small size of expression cassette,it is suitable for efficient transformation in both prokaryotic and eukaryotic organisms.展开更多
A stably transfected CHO cell line coexpressing G551D-CFTR and iodide-sensitive yellow fluorescent protein mutant EYFP-H148Q-I152L was successfully established and used as assay model to identify small-molecule activa...A stably transfected CHO cell line coexpressing G551D-CFTR and iodide-sensitive yellow fluorescent protein mutant EYFP-H148Q-I152L was successfully established and used as assay model to identify small-molecule activators of G551D-CFTR chloride channel from 100000 diverse combinatorial compounds by high throughput screening on a customized Beckman robotic system. A bicyclooctane compound was identified to activate G551D-CFTR chloride channel with high-affinity(K d=1.8 μmol/L). The activity of the bicyclooctane compound is G551D-CFTR-specific, reversible and non-toxic. The G551D-CFTR activator may be useful as a tool to study the mutant G551D-CFTR chloride channel structure and transport properties and as a candidate drug to cure cystic fibrosis caused by G551D-CFTR mutation.展开更多
AIM:To develop a sensitive assay for screening compounds against hepatitis C virus (HCV).METHODS:The proteolytic cleavage of NS3/4A on enhanced yellow fluorescent protein (eYFP)-mitochondrial antiviral signaling prote...AIM:To develop a sensitive assay for screening compounds against hepatitis C virus (HCV).METHODS:The proteolytic cleavage of NS3/4A on enhanced yellow fluorescent protein (eYFP)-mitochondrial antiviral signaling protein (MAVS) was examined by reporter enzyme secreted placental alkaline phosphatase (SEAP),which enabled us to perform ongoing monitoring of anti-HCV drugs through repeated chemiluminescence.Subcellular localization of eYFP-MAVS was assessed by fluorescence microscopy.Cellular localization and protein levels were examined by Western blotting.RESULTS:HCV NS3/4A protease cleaved eYFP-MAVSfrom mitochondria to block the activation of interferon (IFN)-β promoter,thus resulting in downregulation of SEAP activity.The decrease in SEAP activity was proportional to the dose of active NS3/4A protease.Also this reporter assay was used to detect anti-HCV activity of IFN-α and cyclosporine A.CONCLUSION:Our data show that this reporter system is a sensitive and quantitative reporter of anti-HCV inhibitors.This system will constitute a new tool to allow the efficient screening of HCV inhibitors.展开更多
Background: The current screening tools for tuberculosis (TB) are inadequate resulting in insufficient TB case detection and continued community transmission of TB. As the world is geared into finding missing TB cases...Background: The current screening tools for tuberculosis (TB) are inadequate resulting in insufficient TB case detection and continued community transmission of TB. As the world is geared into finding missing TB cases, new strategies are called for to aid in rapid identification of TB cases. This study aimed to evaluate the role C-reactive protein (CRP) in triaging patients to get a definitive test for active pulmonary TB diagnosis in urban Tanzania. Methods: A case-control study was conducted among pulmonary TB (PTB) patients and contacts without active PTB. The diagnosis of PTB was performed using GeneXpert MTB/RIF assay and culture. Blood was collected from cases and controls for measuring CRP levels during recruitment. We compared socio-demographic characteristics, clinical and laboratory parameters obtained during recruitment and performed diagnostic accuracy analyses for CRP. Results: Out of all 193 study participants who were involved in final analysis, 147 (76.2%) were males. Pulmonary TB cases had significantly lower median BMI than controls (median 17.4 kg/m<sup>2</sup> [IQR: 15.8 - 19.2 kg/m<sup>2</sup>] vs., 24.9 kg/m<sup>2</sup> [IQR: 22.1 - 28.5 kg/m<sup>2</sup>), p < 0.001). There was no statistical difference in prevalence of HIV between PTB cases and controls i.e., 13.33% vs., 11.7%, p = 0.48. CRP was significantly higher in PTB cases vs., controls (median 67.8 mg/L, [IQR: 36.5 - 116.9 mg/L] vs., 1.55 mg/L, [IQR: 0.59 - 6.0 mg/L], p = 0.003). Furthermore, CRP at cut-off ≥10 mg/L was associated with best combination of sensitivity, specificity and area under the curve of 89.9%, 95% CI: 82.2 - 95.0, 80.9%, CI: 71.4 - 88.2 and 0.85, 95% CI: 0.80 - 0.90 respectively. A multivariate logistic regression model adjusted for fever, night sweats and body mass index showed that CRP above 10 mg/L was significantly associated with PTB, aOR 5.2, 95% CI 1.2 - 22.8. Conclusions: CRP at cut-off ≥10 mg/L can be used to screen pulmonary TB. These findings can be used to improve TB screening algorithm by incorporating CRP in combination with TB symptoms to identify patients who need further confirmatory TB tests. However, additional prospective studies are required to support our findings and contribute into policy recommendations on use of CRP in a screening algorithm for pulmonary TB.展开更多
Objective To establish a reliable platform for screening glucokinase activators (GKAs) in vitro. Methods Pancreatic glucokinase (PGK) protein expressed in a prokaryotic expression system as a histidine-tagged fusi...Objective To establish a reliable platform for screening glucokinase activators (GKAs) in vitro. Methods Pancreatic glucokinase (PGK) protein expressed in a prokaryotic expression system as a histidine-tagged fusion protein from Homo sapiens was produced. Then, response surface methodology (RSM) was used to optimize the microplate-based GKA screening platform. In the f'trst step of optimization with Plackett-Burman design (PBD), initial pH, reaction time and MgC12 were found to be important factors affecting the activity ratio of GKA (RO-28-1675) significantly. In the second step, a 23 full factorial central composite design (CCD) and RSM were applied to the optimal condition determination of each significant variable. A second-order polynomial was determined by a multiple regression analysis of the experimental data. Results The following optimal values for the critical factors were obtained: initial pH 0 (7.0), reaction time-0.63 (13.7 min) and MgC12 0.11 (2.11 mmol/L) with a predicted value of the maximum activity ratio of 34.1%. Conclusion Under the optimal conditions, the practical activity ratio is 34.8%. The determination coefficient (R2) is 0.9442, ensuring adequate credibility of the model. LLAE3, extracted from Folium nelumbinis in our laboratory, has prominently activated effects on PGK.展开更多
文摘Brazil is the center of diversity and dispersion of species of the genus Passiflora.Two species of passion fruit Passiflora tenuifila BRS VT(passiflora garlic)and another of Passiflora setacea BRS PC were used in this study.The plants were grown on the Embrapa Cerrados experimental farm.The fruits were washed,minimally cut and their constituents separated.Both species differed in the proportion of wet mass between husk,seed,and pulp.As expected,both species had a higher proportion of husks and seeds and a lower amount of pulp.A semi-purification procedure for the proteins present in the seeds and husks was described and the molecular aspects were analyzed by polyacrylamide gel electrophoresis(SDS-PAGE).The quantification of soluble proteins was performed using the Bradford method.The analysis of the soluble protein extracted from the seeds and husks showed that these values are up to 70 times higher for the seeds of P.tenuifila and 28.5 times for P.setacea,in the husks.It was verified that both species present a similar protein profile,observed by the intense and diverse bands found in the polyacrylamide gel,mainly in the range of 32 to 19 kDa.This work opens up an unexplored field of tracking bioactive proteins and/or peptides including forms of nanostructure systems that protect other bioactive molecules.The objective of this work was to present an analytical procedure to semi-purify seed proteins of two Passiflora species and use electrophoresis as an analysis tool for further screening of their protein profiles and selection of a molecular marker to differentiate them.
基金supported by grants from the Key Project of Guangzhou(No.1561000151)the Yangtze River Scholarship(No.85000-52121100)+1 种基金the National Nature Science Foundation in China(No.81530081,31571395)the 973 project(No.2012CB967000)
文摘The regulation of protein stability is a fundamental issue for biophysical processes,but there has not previously been a convenient and unbiased method of identifying regulators of protein stability.However,as reported in the article entitled "A genome-scale CRISPR-Cas9 screening method for protein stability reveals novel regulators of Cdc25 A," recently published in Cell Discovery,our team developed a protein stability regulators screening assay(Pro-SRSA) by combining the whole-genome clustered regularly interspaced short palindromic repeats Cas9(CRISPR-Cas9) library with a dual-fluorescence-based protein stability reporter and high-throughput sequencing to screen for regulators of protein stability.Based on our findings,we are confident that this efficient and unbiased screening method at the genome scale will be used by researchers worldwide to identify regulators of protein stability.
基金the National Natural Science Foundation of China, No. 30300116
文摘The present study screened a human fetal brain cDNA library to find the proteins that interact with mutant superoxide dismutase 1 (SOD1) using a yeast two-hybrid system. Using BLAST software, 15 real proteins which interacted with mutant SOD1 were obtained, including 8 known proteins (protein tyrosine-phosphatase non-receptor type 2, TBCl D4, protein kinase family, splicing factor, arginine/serine-rich 2, SRC protein tyrosine kinase Fyn, β-sarcoglycan; glycine receptor a2, microtubule associated protein/microtubule affinity-regulating kinase 1, ferritin H chain), and 7 unknown proteins. Results demonstrated interaction of mutant SOD1 with microtubule associated protein/microtubule affinity-regulating kinase 1 and β-sarcoglycan.
文摘A Flp/FRT EMS mutagenesis screen was conducted in the eye of Drosophila melanogaster on chromosome 2R to identify negative regulators of cell growth and cell division. In addition to the EMS mutation in the mosaic eye, an ark loss of function allele (ark<sup>82</sup>) was utilized to block apoptosis in the homozygous mutant cells, setting up a screen for conditional regulators of cell growth and cell division. In the present study, we focus on the characterization and mapping of one mutant that resulted from this screen, Cruella (cru). A cross between flies with the flippase enzyme directed to the developing eye and flies with the mutations cru, ark<sup>82</sup>, revealed an unusual phenotype that resulted in the homozygous mutant tissue appearing black, in contrast to the expected red. To map the location of this mutation, complementation tests against the Bloomington deficiency kit were conducted. Cru failed to complement previously characterized alleles of capping protein α (cpa). Thus, cpa<sup>cru</sup> is a novel allele of cpa and displays phenotypes similar to previously characterized alleles such as cpa 107E, cpa 69E, and cpa<sup>scrd</sup> . The human homolog, Cap Z, is conserved in humans and serves a similar role in act in filament regulation.
基金supported by the National Natural Science Foundation of China(21102181,81302634 and 21572273)
文摘BRAF has been recognized as a promising target for cancer therapy. A number of crystal structures have been published. Molecular docking is one of the most effective techniques in the field of computer-aided drug design(CADD). Appropriate protein conformation and docking method are essential for the successful virtual screening experiments. One approach considering protein flexibility and multiple docking methods was proposed in this study. Six DFG-in/αC-helix-out crystal structures of BRAF, three docking programs(Glide, GOLD and Ligand Fit) and 12 scoring functions were applied for the best combination by judging from the results of pose prediction and retrospective virtual screening(VS). The most accurate results(mean RMSD of about 0.6 A) of pose prediction were obtained with two complex structures(PDB: 3 C4 C and 3 SKC) using Glide SP. From the retrospective VS, the most active compounds were identified by using the complex structure of 3 SKC, indicated by a ROC/AUC score of 0.998 and an EF of 20.6 at 5% of the database screen with Glide-SP. On the whole, PDB 3 SKC could achieve a higher rate of correct reproduction, a better enrichment and more diverse compounds. A comparison of 3 SKC and the other X-ray crystal structures led to a rationale for the docking results. PDB 3 SKC could achieve a broad range of sulfonamide substitutions through an expanded hydrophobic pocket formed by a further shift of the αC-helix. Our study emphasized the necessity and significance of protein flexibility and scoring functions in both ligand docking and virtual screening.
基金Supported by grants of the National Natural Science Foundation of China(31071203,31370789,31670789,and 31671316)
文摘Objective To screen the transient and stable cell lines with high production of Nectin-like 4(Necl-4)protein.Methods First,c DNA sequences encoding the extracellular domain of Necls were cloned into the modified vector p APtag at the N terminus of alkaline phosphatase(AP)for fusion expression.Next,293ET cells stably expressed Necls-AP fusion protein and secreted it into the culture medium which were detected by the AP activity assay and Western blot analysis.Then,by adding N-glycosylation processing inhibitor kifunensine into the medium,complex glycan was inhibited to generate.The residual glycan of purified protein was removed by endoglycosidase H.Finally,AP protein was removed by using human rhinovirus protease and size exclusion chromatography.The concentration of purified Necl-4 protein was monitored by measuring the absorbance at280 nm and analyzed by SDS-PAGE.Results The transient and stable cell lines with high production of Necl-4 protein were screened by the color reaction with the AP-tag in the recombinant vector.The soluble and active form of purified Necl-4 protein was obtained after deglycosylation of native N-glycan protein with an expression level of 4 mg/L culture and purity of 95%.Conclusions By using modified AP mammalian protein expression system,we can easily screen the high productive stable cell lines by using AP activity assay.By adding mannosidase inhibitor kifunensine into the medium and cutting purified protein by using endoglycosidase H,we can obtain deglycosylated Necl-4 protein in milligram quantities.Our method might throw a light on the expression and purification of glycoprotein for structural and functional studies.
基金supported by the National Natural Science Foundation of China (31500237)
文摘Recently, a novel green fluorescent protein eYGFPuv has been identified in the marine organism Chiridius poppei which displays high fluorescence intensity and can be visible by eyes in dark. Although strong green fluorescence was achieved in transgenic petunia, 3 expression cassettes (about 8 kb) complicate its application. In this study, to confirm whether 1 expression cassette could be used as a transgenic marker in prokaryotes and eukaryotes, eYGFPuv was cloned into prokaryotic expression vector pET28α-eYGFPuv- His and plant binary expression vector 35S::eYGFPuv. Compared to EGFP, eYGFPuv protein exhibited stronger dazzling green fluorescence in E. coli under excited light at 365 nm and maintains steadily over a long period of time without degradation. When transiently expressed in tobacco leaves, eYGFPuv protein displayed strong green fluorescence. Moreover, the fluorescence of eYGFPuv protein also could be directly observed in living plant, and thus can be used easily as a marker to screen transformed lines in transgenic research. Overall, compared to previous studies on eYGFPuv tandem repeats, our data confirmed that single eYGFPuv sequence still possesses high fluorescence intensity and quenching resistance. Furthermore, because of small size of expression cassette,it is suitable for efficient transformation in both prokaryotic and eukaryotic organisms.
基金the Start- up Fund for Returned Overseas Scholars from Northeast Normal U niversity,National ScienceFund for Distinguished Young Scholars (No. 30 32 5 0 11) ,Distinguished Young Scholars Fund of Jilin Province(No.2 0 0 30 112 ) ,Excellent Young Teachers
文摘A stably transfected CHO cell line coexpressing G551D-CFTR and iodide-sensitive yellow fluorescent protein mutant EYFP-H148Q-I152L was successfully established and used as assay model to identify small-molecule activators of G551D-CFTR chloride channel from 100000 diverse combinatorial compounds by high throughput screening on a customized Beckman robotic system. A bicyclooctane compound was identified to activate G551D-CFTR chloride channel with high-affinity(K d=1.8 μmol/L). The activity of the bicyclooctane compound is G551D-CFTR-specific, reversible and non-toxic. The G551D-CFTR activator may be useful as a tool to study the mutant G551D-CFTR chloride channel structure and transport properties and as a candidate drug to cure cystic fibrosis caused by G551D-CFTR mutation.
基金Supported by The Natural Science Foundation of China,No.30600330,No.30671842,No.30672488,No.30700475,No.30771919and No.30700757the National High Technology Research and Development Program of China,No.2008AA02Z132+1 种基金Beijing Municipal Natural Science Foundation,No.5082016Mega-projects of Science Research for the 11th Five-Year Plan,No.2009ZX10004-4001
文摘AIM:To develop a sensitive assay for screening compounds against hepatitis C virus (HCV).METHODS:The proteolytic cleavage of NS3/4A on enhanced yellow fluorescent protein (eYFP)-mitochondrial antiviral signaling protein (MAVS) was examined by reporter enzyme secreted placental alkaline phosphatase (SEAP),which enabled us to perform ongoing monitoring of anti-HCV drugs through repeated chemiluminescence.Subcellular localization of eYFP-MAVS was assessed by fluorescence microscopy.Cellular localization and protein levels were examined by Western blotting.RESULTS:HCV NS3/4A protease cleaved eYFP-MAVSfrom mitochondria to block the activation of interferon (IFN)-β promoter,thus resulting in downregulation of SEAP activity.The decrease in SEAP activity was proportional to the dose of active NS3/4A protease.Also this reporter assay was used to detect anti-HCV activity of IFN-α and cyclosporine A.CONCLUSION:Our data show that this reporter system is a sensitive and quantitative reporter of anti-HCV inhibitors.This system will constitute a new tool to allow the efficient screening of HCV inhibitors.
文摘Background: The current screening tools for tuberculosis (TB) are inadequate resulting in insufficient TB case detection and continued community transmission of TB. As the world is geared into finding missing TB cases, new strategies are called for to aid in rapid identification of TB cases. This study aimed to evaluate the role C-reactive protein (CRP) in triaging patients to get a definitive test for active pulmonary TB diagnosis in urban Tanzania. Methods: A case-control study was conducted among pulmonary TB (PTB) patients and contacts without active PTB. The diagnosis of PTB was performed using GeneXpert MTB/RIF assay and culture. Blood was collected from cases and controls for measuring CRP levels during recruitment. We compared socio-demographic characteristics, clinical and laboratory parameters obtained during recruitment and performed diagnostic accuracy analyses for CRP. Results: Out of all 193 study participants who were involved in final analysis, 147 (76.2%) were males. Pulmonary TB cases had significantly lower median BMI than controls (median 17.4 kg/m<sup>2</sup> [IQR: 15.8 - 19.2 kg/m<sup>2</sup>] vs., 24.9 kg/m<sup>2</sup> [IQR: 22.1 - 28.5 kg/m<sup>2</sup>), p < 0.001). There was no statistical difference in prevalence of HIV between PTB cases and controls i.e., 13.33% vs., 11.7%, p = 0.48. CRP was significantly higher in PTB cases vs., controls (median 67.8 mg/L, [IQR: 36.5 - 116.9 mg/L] vs., 1.55 mg/L, [IQR: 0.59 - 6.0 mg/L], p = 0.003). Furthermore, CRP at cut-off ≥10 mg/L was associated with best combination of sensitivity, specificity and area under the curve of 89.9%, 95% CI: 82.2 - 95.0, 80.9%, CI: 71.4 - 88.2 and 0.85, 95% CI: 0.80 - 0.90 respectively. A multivariate logistic regression model adjusted for fever, night sweats and body mass index showed that CRP above 10 mg/L was significantly associated with PTB, aOR 5.2, 95% CI 1.2 - 22.8. Conclusions: CRP at cut-off ≥10 mg/L can be used to screen pulmonary TB. These findings can be used to improve TB screening algorithm by incorporating CRP in combination with TB symptoms to identify patients who need further confirmatory TB tests. However, additional prospective studies are required to support our findings and contribute into policy recommendations on use of CRP in a screening algorithm for pulmonary TB.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University,PCSERT(No.IRT0540).
文摘Objective To establish a reliable platform for screening glucokinase activators (GKAs) in vitro. Methods Pancreatic glucokinase (PGK) protein expressed in a prokaryotic expression system as a histidine-tagged fusion protein from Homo sapiens was produced. Then, response surface methodology (RSM) was used to optimize the microplate-based GKA screening platform. In the f'trst step of optimization with Plackett-Burman design (PBD), initial pH, reaction time and MgC12 were found to be important factors affecting the activity ratio of GKA (RO-28-1675) significantly. In the second step, a 23 full factorial central composite design (CCD) and RSM were applied to the optimal condition determination of each significant variable. A second-order polynomial was determined by a multiple regression analysis of the experimental data. Results The following optimal values for the critical factors were obtained: initial pH 0 (7.0), reaction time-0.63 (13.7 min) and MgC12 0.11 (2.11 mmol/L) with a predicted value of the maximum activity ratio of 34.1%. Conclusion Under the optimal conditions, the practical activity ratio is 34.8%. The determination coefficient (R2) is 0.9442, ensuring adequate credibility of the model. LLAE3, extracted from Folium nelumbinis in our laboratory, has prominently activated effects on PGK.