The effect of pH values on the extracellular protein and polysaccharide secretions of Acidithiobacillus ferrooxidans was comparatively investigated in different phases of bacterial growth during chalcopyrite bioleachi...The effect of pH values on the extracellular protein and polysaccharide secretions of Acidithiobacillus ferrooxidans was comparatively investigated in different phases of bacterial growth during chalcopyrite bioleaching. The results indicate that the extracellular protein is always more than the extracellular polysaccharide secreted by attached cells on the chalcopyrite, on the contrary, and is always less than the extracellular polysaccharide secreted by free cells in the solution at bacterial adaptive phase, logarithmic phase and stationary phase whenever pH value is at 1.0, 1.5, 2.0 or 2.5; free cells are mainly through the secretion of extracellular polysaccharide rather than the extracellular protein to fight against disadvantageous solution environment, such as high concentration of metal ions and unsuitable pH solution; both amounts of polysaccharide and protein secreted by attached cells are mainly positively related to the solution acidity rather than the total concentration of soluble metal ions. The experimental results imply that bacteria are mainly through secreting more extracellular polysaccharide to fight against disadvantageous environment and the extracellular protein perhaps plays an important role in oxidation？reduction reactions in the bioleaching system.展开更多
Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A ...Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A cell suspension culture was initiated from callus derived from plantlets of Populus euphratica. Cold acclimation was induced (LT50 of 17.5 ℃) in cell suspension at 45 ℃ in the dark for 30 days and the freezing tolerance increased from LT50 of 12.5 ℃ in nonacclimated cells to LT50 of 17.5 ℃ in cold-acclimated cells. Microvacuolation, cytoplasmic augmentation and accumulation of starch granules were observed in cells that were cold-acclimated by exposure to low temperatures. Several qualitative and quantitative changes in proteins were noted during cold acclimation. Antibodies to carrot extracellular (apoplastic) 36 kD antifreeze protein did not cross react on immunoelectroblots with extracellular proteins in cell suspension culture medium of Populus euphratica, indicating no common epitopes in the carrot 36 kD antifreeze protein and P. euphratica extracellular proteins. The relationship of these changes to cold acclimation in Populus euphratica cell cultures was discussed.展开更多
Escherichia coli type 1 was used as a model system to determine whether static magnetic fields are a general stress factor. The bacterial broth culture were exposed to different magnetic force （400, 800, 1200 and 160...Escherichia coli type 1 was used as a model system to determine whether static magnetic fields are a general stress factor. The bacterial broth culture were exposed to different magnetic force （400, 800, 1200 and 1600 Gauss） with incubation at 37 ℃ for different times （24, 48 and 72 hrs） under aerobic conditions. The response of the cells to the magnetic fields was estimated from the change in total protein synthesis by using spectrophotometer at 550 nm and by using of SDS-PAGE （Sodium dodecyl sulfate- polyacrylamide gel electrophoresis）. Results concluded that was approximately no reproducible changes qualitatively in extracellular proteins were observed in the SDS-PAGE electrophoresis and did not act as a general stress factor. While, increases in the level of extra-cellular synthesis were observed using different magnetic field exposed samples when compared with the control.展开更多
[Objective] The research aimed to find the extracellular binding proteins of CR4.[Method] The extracellular domain of OsCR4 was as the bait protein,and the yeast two-hybrid was used to screen cDNA library of seedling ...[Objective] The research aimed to find the extracellular binding proteins of CR4.[Method] The extracellular domain of OsCR4 was as the bait protein,and the yeast two-hybrid was used to screen cDNA library of seedling which was cultivated 14 d.[Result] A lot of proteins which included a peroxide B（D26484）,a methionine thioredoxin reductase（ABF96078）and an unknown function protein were gained.[Conclusion] It provided the theory basis for studying the signal transduction mechanism of CR4.展开更多
Riemerella anatipestifer is the causative agent of septicemia anserum exsudativa in ducks. Its pathogenesis and virulence factors are still unclear. The glycelytic enzyme, glyceraldehyde-3-phosphate dehydrogenase （GA...Riemerella anatipestifer is the causative agent of septicemia anserum exsudativa in ducks. Its pathogenesis and virulence factors are still unclear. The glycelytic enzyme, glyceraldehyde-3-phosphate dehydrogenase （GAPDH）, an anchorless and multifunctional protein on the surface of several pathogenic microorganisms, is involved in virulence and adhesion. Whether homologs of GAPDH exist, and display similar characteristics in R. anatipestifer （RaGAPDH） has not been determined. In our research, the RaGAPDH activity from various R. anatipestifer isolates was confirmed. Twenty-two gapdh genes from genornic DNA of R. anatipestifer isolates were cloned and sequenced for phylogenetic analysis. The distribution of RaGAPDH in R. anatipestifer CZ2 strain was confirmed by antisera to recombinant RaGAPDH. The ability of purified RaGAPDH to bind host proteins was analyzed by solid-phase ligandbinding assay. Results revealed that all R. anatipestifer isolates showed different levels of GAPDH activity except four strains, which contained a gapdh-like gene. The gapdh of R. anatipestifer, which is located phylogenetically in the same branch as enterohemorrhagic Escherichia coil （EHEC）, belonged to class I GAPDH, and encoded a 36.7-kDa protein. All RaGAPDH-encoding gene sequences from field isolates of R. anatipestiferdisplayed 100% homology. The RaGAPDH localized on the extracellular membrane of several R. anatipestifer strains. Further, it was released into the culture medium, and exhibited GAPDH enzyme activity. We also confirmed the binding of RaGAPDH to plasminogen and fibrinogen. These results demonstrated that GAPDH was present in R. anatipestifer, although not in all strains, and that RaGAPDH might contribute to the microorganism＇s virulence.展开更多
Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-N...Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.展开更多
Mammalian cells express two isoforms of Cu- and Zn-containing superoxide dismutases（SODs）, CuZn-SOD and extracellular SOD（EC-SOD）, involved in the defense system against reactive oxygen species（ROS）. The two SOD...Mammalian cells express two isoforms of Cu- and Zn-containing superoxide dismutases（SODs）, CuZn-SOD and extracellular SOD（EC-SOD）, involved in the defense system against reactive oxygen species（ROS）. The two SODs have structurally homologous centre domain with distinct N- and C-terminuses, resulting in the different characteristics of the structure and function of the two molecules. We generated a hybrid SOD molecule（namely hy- SOD） via replacing the N- and C-terminuses of hCuZnSOD with the counterparts of hEC-SOD. The hySOD was expressed in host Pichia pastoris and the purified protein was a dimer with a molecular weight of about 34000. A series of activity analyses indicates that the hySOD is similar to hEC-SOD in heat-stability, and has the activity of protecting the host cell against heat shock and oxidative stress. Our results show evidence for the study on the compound activity of multiple SOD molecules, and may be important for understanding the relationship between structure and function of hEC-SOD and hCuZnSOD.展开更多
The purpose of this study was to investigate changes of β 3 integrins and extra cellular matrix proteins including fibronectin (FN), laminin (LN) and collagen type Ⅳ (CL typeⅣ) on the endometrium of secret...The purpose of this study was to investigate changes of β 3 integrins and extra cellular matrix proteins including fibronectin (FN), laminin (LN) and collagen type Ⅳ (CL typeⅣ) on the endometrium of secretory phase from 31 fertile women (fertility group)and 34 women with unexplained infertility (infertility group) by a histochemical method.The results were as follows:In glandular epithelium, β 3 integrin appeared in the mid secretory phase and continued to late secretory phase in the fertility group, but was not expressed during the secretory phase in the infertility group. Extracellular matrix proteins from the fertility group were expressed more strongly in mid secretory phase than that in the early secretory phase, and were weakest in the late secretory phase. Compared with the fertility group, the levels of extracellular matrix proteins in the infertility group were elevated in the secretory phase. In conclusion: our current study demonstrate that β 3 integrin and extracellular matrix proteins are expressed at different levels in the endometrium during the menstrual cycle. They are involved in endometrial changes during the menstrual cycle and during the implantation of the blastocyst. Their unusual expression result in the failure of implantation.展开更多
Collagens are the most abundant proteins in mammals and form an extracellular matrix (ECM) with other components as the structural support of muscle, skin, corneas and blood vessels etc. Other than providing structura...Collagens are the most abundant proteins in mammals and form an extracellular matrix (ECM) with other components as the structural support of muscle, skin, corneas and blood vessels etc. Other than providing structural support, the ECM exhibits active communication with cells and influences many cellular processes including migration, wound healing, differentiation and cancer metastasis. Though collagen proteins contain highly repetitive primary sequences and defined tertiary structures, more and more studies have shown that many short peptides/motifs within collagen proteins play key roles in various biological processes. These short sequences are effective within triple helical structures or independently as stand-alone molecules resulting from proteolytic degradation. Besides endogenous ECM-derived peptides, many more functional peptides have been produced by tissue processing, chemical synthesis, and recombinant protein production. In this review, we summarize different peptides/motifs identified in collagen and other ECM proteins and discuss their potential for medical, personal care, and cosmetics applications.展开更多
基金Project(31200382)supported by the National Natural Science Foundation of China
文摘The effect of pH values on the extracellular protein and polysaccharide secretions of Acidithiobacillus ferrooxidans was comparatively investigated in different phases of bacterial growth during chalcopyrite bioleaching. The results indicate that the extracellular protein is always more than the extracellular polysaccharide secreted by attached cells on the chalcopyrite, on the contrary, and is always less than the extracellular polysaccharide secreted by free cells in the solution at bacterial adaptive phase, logarithmic phase and stationary phase whenever pH value is at 1.0, 1.5, 2.0 or 2.5; free cells are mainly through the secretion of extracellular polysaccharide rather than the extracellular protein to fight against disadvantageous solution environment, such as high concentration of metal ions and unsuitable pH solution; both amounts of polysaccharide and protein secreted by attached cells are mainly positively related to the solution acidity rather than the total concentration of soluble metal ions. The experimental results imply that bacteria are mainly through secreting more extracellular polysaccharide to fight against disadvantageous environment and the extracellular protein perhaps plays an important role in oxidation？reduction reactions in the bioleaching system.
基金the National Natural Science Foundation of China (Grant No. 30271067)Fok Ying Tung Education Foundation (71030)+1 种基金 Key Teachers Foundation of the Educational Ministry of China and the State Key Basic Research and Development Plan of China (G199901600
文摘Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A cell suspension culture was initiated from callus derived from plantlets of Populus euphratica. Cold acclimation was induced (LT50 of 17.5 ℃) in cell suspension at 45 ℃ in the dark for 30 days and the freezing tolerance increased from LT50 of 12.5 ℃ in nonacclimated cells to LT50 of 17.5 ℃ in cold-acclimated cells. Microvacuolation, cytoplasmic augmentation and accumulation of starch granules were observed in cells that were cold-acclimated by exposure to low temperatures. Several qualitative and quantitative changes in proteins were noted during cold acclimation. Antibodies to carrot extracellular (apoplastic) 36 kD antifreeze protein did not cross react on immunoelectroblots with extracellular proteins in cell suspension culture medium of Populus euphratica, indicating no common epitopes in the carrot 36 kD antifreeze protein and P. euphratica extracellular proteins. The relationship of these changes to cold acclimation in Populus euphratica cell cultures was discussed.
文摘Escherichia coli type 1 was used as a model system to determine whether static magnetic fields are a general stress factor. The bacterial broth culture were exposed to different magnetic force （400, 800, 1200 and 1600 Gauss） with incubation at 37 ℃ for different times （24, 48 and 72 hrs） under aerobic conditions. The response of the cells to the magnetic fields was estimated from the change in total protein synthesis by using spectrophotometer at 550 nm and by using of SDS-PAGE （Sodium dodecyl sulfate- polyacrylamide gel electrophoresis）. Results concluded that was approximately no reproducible changes qualitatively in extracellular proteins were observed in the SDS-PAGE electrophoresis and did not act as a general stress factor. While, increases in the level of extra-cellular synthesis were observed using different magnetic field exposed samples when compared with the control.
基金Project(50674101)supported by the National Natural Science Foundation of ChinaProject(2004CB619201)supported by the National Basic Research Program of ChinaProject(50621063)supported by the Chinese Science Foundation for Distinguished Group
基金Supported by Science Technology Research and Development Project in Shijiazhuang City in2010(10120803)Scientific Research Starting Fund Project of Shijiazhuang University in2007(2007012),Education Reform Research Item of Shijiazhuang University in2008(2008006)~~
文摘[Objective] The research aimed to find the extracellular binding proteins of CR4.[Method] The extracellular domain of OsCR4 was as the bait protein,and the yeast two-hybrid was used to screen cDNA library of seedling which was cultivated 14 d.[Result] A lot of proteins which included a peroxide B（D26484）,a methionine thioredoxin reductase（ABF96078）and an unknown function protein were gained.[Conclusion] It provided the theory basis for studying the signal transduction mechanism of CR4.
基金Project supported by the Fundamental Research Funds of the Central Universities of China(No.XDJK2013C009)
文摘Riemerella anatipestifer is the causative agent of septicemia anserum exsudativa in ducks. Its pathogenesis and virulence factors are still unclear. The glycelytic enzyme, glyceraldehyde-3-phosphate dehydrogenase （GAPDH）, an anchorless and multifunctional protein on the surface of several pathogenic microorganisms, is involved in virulence and adhesion. Whether homologs of GAPDH exist, and display similar characteristics in R. anatipestifer （RaGAPDH） has not been determined. In our research, the RaGAPDH activity from various R. anatipestifer isolates was confirmed. Twenty-two gapdh genes from genornic DNA of R. anatipestifer isolates were cloned and sequenced for phylogenetic analysis. The distribution of RaGAPDH in R. anatipestifer CZ2 strain was confirmed by antisera to recombinant RaGAPDH. The ability of purified RaGAPDH to bind host proteins was analyzed by solid-phase ligandbinding assay. Results revealed that all R. anatipestifer isolates showed different levels of GAPDH activity except four strains, which contained a gapdh-like gene. The gapdh of R. anatipestifer, which is located phylogenetically in the same branch as enterohemorrhagic Escherichia coil （EHEC）, belonged to class I GAPDH, and encoded a 36.7-kDa protein. All RaGAPDH-encoding gene sequences from field isolates of R. anatipestiferdisplayed 100% homology. The RaGAPDH localized on the extracellular membrane of several R. anatipestifer strains. Further, it was released into the culture medium, and exhibited GAPDH enzyme activity. We also confirmed the binding of RaGAPDH to plasminogen and fibrinogen. These results demonstrated that GAPDH was present in R. anatipestifer, although not in all strains, and that RaGAPDH might contribute to the microorganism＇s virulence.
基金Supported by National Natural Science Foundation of China (30421003,30828004)
文摘Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.
文摘Mammalian cells express two isoforms of Cu- and Zn-containing superoxide dismutases（SODs）, CuZn-SOD and extracellular SOD（EC-SOD）, involved in the defense system against reactive oxygen species（ROS）. The two SODs have structurally homologous centre domain with distinct N- and C-terminuses, resulting in the different characteristics of the structure and function of the two molecules. We generated a hybrid SOD molecule（namely hy- SOD） via replacing the N- and C-terminuses of hCuZnSOD with the counterparts of hEC-SOD. The hySOD was expressed in host Pichia pastoris and the purified protein was a dimer with a molecular weight of about 34000. A series of activity analyses indicates that the hySOD is similar to hEC-SOD in heat-stability, and has the activity of protecting the host cell against heat shock and oxidative stress. Our results show evidence for the study on the compound activity of multiple SOD molecules, and may be important for understanding the relationship between structure and function of hEC-SOD and hCuZnSOD.
文摘The purpose of this study was to investigate changes of β 3 integrins and extra cellular matrix proteins including fibronectin (FN), laminin (LN) and collagen type Ⅳ (CL typeⅣ) on the endometrium of secretory phase from 31 fertile women (fertility group)and 34 women with unexplained infertility (infertility group) by a histochemical method.The results were as follows:In glandular epithelium, β 3 integrin appeared in the mid secretory phase and continued to late secretory phase in the fertility group, but was not expressed during the secretory phase in the infertility group. Extracellular matrix proteins from the fertility group were expressed more strongly in mid secretory phase than that in the early secretory phase, and were weakest in the late secretory phase. Compared with the fertility group, the levels of extracellular matrix proteins in the infertility group were elevated in the secretory phase. In conclusion: our current study demonstrate that β 3 integrin and extracellular matrix proteins are expressed at different levels in the endometrium during the menstrual cycle. They are involved in endometrial changes during the menstrual cycle and during the implantation of the blastocyst. Their unusual expression result in the failure of implantation.
文摘Collagens are the most abundant proteins in mammals and form an extracellular matrix (ECM) with other components as the structural support of muscle, skin, corneas and blood vessels etc. Other than providing structural support, the ECM exhibits active communication with cells and influences many cellular processes including migration, wound healing, differentiation and cancer metastasis. Though collagen proteins contain highly repetitive primary sequences and defined tertiary structures, more and more studies have shown that many short peptides/motifs within collagen proteins play key roles in various biological processes. These short sequences are effective within triple helical structures or independently as stand-alone molecules resulting from proteolytic degradation. Besides endogenous ECM-derived peptides, many more functional peptides have been produced by tissue processing, chemical synthesis, and recombinant protein production. In this review, we summarize different peptides/motifs identified in collagen and other ECM proteins and discuss their potential for medical, personal care, and cosmetics applications.
