The expression of a rice Cu/Zn superoxide dismutase （Cu/Zn-SOD） in Saccharomyces cerevisiae regulated by GAPDH promoter, involved in the inhibition of endogenous Glutathione （GSH） synthesis, and the competitive ex...The expression of a rice Cu/Zn superoxide dismutase （Cu/Zn-SOD） in Saccharomyces cerevisiae regulated by GAPDH promoter, involved in the inhibition of endogenous Glutathione （GSH） synthesis, and the competitive expression was detected by constructing the expression vector transferred Cu/Zn-SOD gene into wild-type S. cerevisiae. Transcription and expression of the Cu/Zn-SOD gene in S. cerevisiawere were confirmed by northern blot and SDS-PAGE, respectively, and activity of the Cu/Zn-SOD from crude extracts was enzymatically detected based on the effect of nitroblue tetrazolium （NBT） after running a native polyacrylamide gel. The GSH synthesis was also tested by DTNB （5, 5＇-Dithiobis （2-nitrobenzoic acid）） method. Results showed that GSH synthesis was evidently suppressed by the expression of Cu/Zn-SOD gene in both control and heat shock strains. It implied that the expression of the Cu/Zn-SOD gene in S. cerevisiae has more potential facility in response to oxidative exposure than that of endogenous GSH, although Cu/Zn-SOD and GSH were both contributed to the function of oxygen radical oxidoreduction.展开更多
AIM: To investigate the effects of hydrogen(H2) on Cu, Zn superoxide dismutase(SOD1) activation in a rat model of corneal alkali burn. METHODS: In each rat, one cornea was subjected to alkali exposure. Physiological s...AIM: To investigate the effects of hydrogen(H2) on Cu, Zn superoxide dismutase(SOD1) activation in a rat model of corneal alkali burn. METHODS: In each rat, one cornea was subjected to alkali exposure. Physiological saline(saline group) or H2-dissolved saline(H2 group) was instilled continuously on the cornea for 5 min before and after alkali exposure. Inflammatory cells, neovascularization, and cytoplasmic SOD1 levels were evaluated immunohistochemically in enucleated eyes from both groups. Three-dimensional ultrastructural tissue changes in the eyes were analyzed using low-vacuum scanning electron microscopy.RESULTS: The numbers of both inflammatory and vascular endothelial cells were significantly reduced in the corneas of the H2 group(P<0.01). Furthermore, H2 treatment increased both cytoplasmic SOD1 levels(P<0.01) and activity in corneal epithelial cells(P<0.01). Notably, the SOD1 activity level in the H2 group was approximately 2.5-fold greater than that in the saline group.CONCLUSION: H2 treatment suppresses inflammation and neovascularization in the injured cornea and indirectly suppresses oxidative insult to the cornea by upregulating the SOD1 enzyme protein level and activity.展开更多
Cu/Zn-superoxide dismutase (Cu/Zn-SOD) is an enzyme that is ubiquitously present in the cytoplasm and causes dismutation of superoxide radicals, therefore Cu/Zn-SOD is primarily used as an antioxidant marker. Levels o...Cu/Zn-superoxide dismutase (Cu/Zn-SOD) is an enzyme that is ubiquitously present in the cytoplasm and causes dismutation of superoxide radicals, therefore Cu/Zn-SOD is primarily used as an antioxidant marker. Levels of Cu/Zn-SOD are higher in the serum of hemodialysis patients than in serum of healthy volunteers. The increase of serum Cu/Zn-SOD levels is related to the decrease of kidney function with aging and arteriosclerosis in hemodialysis patients. Moreover, infection, vascular puncture, and hemostasis may be related to the increase in serum Cu/Zn-SOD levels. As it is associated with numerous factors in hemodialysis patients, Cu/Zn-SOD may serve as a complex marker for arteriosclerosis, vascular, and inflammatory conditions. It is important to investigate various agents that decrease serum Cu/Zn-SOD levels to improve the life-span of hemodialysis patients.展开更多
Objective:To determine the activity of superoxide dismutase(SOD) in the male and female haematophagous caprine worms,Haemonchus contortus infecting Capra hircus,and their E/S products and also to analyse the effect of...Objective:To determine the activity of superoxide dismutase(SOD) in the male and female haematophagous caprine worms,Haemonchus contortus infecting Capra hircus,and their E/S products and also to analyse the effect of Haemonchus infection on the level of host SOD.Methods:The SOD activity was analysed by using the pyrogallol autoxidation assay and non-denaturing polyacrylamide gel electrophoresis followed by specific enzyme staining by riboflavin-nitroblue tetrazolium method.Results:The adult females were found to have higher enzyme activity than the male worms.Appreciable amount of SOD activity was also detected in the worm culture medium and female worms secreted more SOD in comparison to the male parasites.The SOD activity was negatively correlated to the worm burden.Statistically significant decrease in SOD activity(P<0.05) was observed in the heavily infected host tissue in comparison to the control non-infected host tissue.SOD profile of the crude extracts of both the sexes revealed polymorphism and a fast migrating activity band being characteristic of E/S products.The SOD activities were found highly sensitive to potassium cyanide indicating the Cu/Zn form of SOD.Conclusions:Haemonchus contortus is a key model parasite for drug and vaccine discovery.The presences of SOD activity in appreciable amount in the parasite as well as its E/S products indicate that it has a well-developed active antioxidant system to protect itself from the host immune attack.SOD could be the target for vaccine development which is the need of the hour as mass drug administration for parasite control has resulted in anthelmintic resistance across the globe and threatens the viability of sheep and goat industry in many regions of the world.The infection with Haemonchus causes a drastic reduction in SOD activity of the host tissue thus effecting its protective potential.One characteristic SOD band was found in the females which was not present in any other preparations and thus could be exploited for further studies on diagnostic/control measures.展开更多
Superoxide dismutase(SOD) is an important antioxidant enzyme in the body. SOD has special physiological activity and is the primary substance for scavenging free radicals in living organisms.However, the expensive and...Superoxide dismutase(SOD) is an important antioxidant enzyme in the body. SOD has special physiological activity and is the primary substance for scavenging free radicals in living organisms.However, the expensive and complex extraction processes, low SOD yield, as well as difficult to store at room temperature have seriously hindered its application pace. Herein, the enzyme mimetic function of Mn-doped ZnS quantum dots(QDs) was discovered. The improved Marklund and McCord method both showed that Mn-doped ZnS QDs possess intrinsic SOD-like activity. The effects of temperature and pH on the mimetic enzyme activity of Mn-doped ZnS QDs have been investigated compared with SOD enzymes.The low cost and easy to synthesize white Mn-doped ZnS QDs with good biocompatibility are expected to be used as a new type of SOD nanozymes in the biology-relevant fields.展开更多
Superoxide dismutases （SODs） are a group of important antioxidant defense enzymes. In this study, a putative extracellular Cu/Zn superoxide dismutase （ecCuZnSOD） complementary DNA was cloned and characterized from...Superoxide dismutases （SODs） are a group of important antioxidant defense enzymes. In this study, a putative extracellular Cu/Zn superoxide dismutase （ecCuZnSOD） complementary DNA was cloned and characterized from the whitefly, Bemisia tabaci. Quantitative polymerase chain reaction analysis showed that the expression level of BtecCuZnSOD was more than 10-fold higher in the invasive Middle East Asia Minor 1 （MEAM1） than in the native Asia II 3 species of the B. tabaci species complex. After exposure to low temperature （4 ℃）, the expression of Bt-ecCuZnSOD gene was significantly up-regulated in MEAM1 but not in Asia II 3. Furthermore, the expression level ofB. tabaci intracellular CuZnSOD （Bt-icCuZnSOD）, Bt-ecCuZnSOD and mitochondrial MnSOD （Bt-mMnSOD） was compared after transferring MEAM1 and Asia II 3 whiteflies from favorable （cotton） to unfavorable host plants （tobacco）. On cotton, both CuZnSOD genes were expressed at a higher level in MEAM1 compared with Asia II 3. Interestingly, after transferring onto tobacco, the expression of Bt-ecCuZnSOD was significantly induced in Asia II 3 but not in MEAM1. On the other hand, while Bt-mMnSOD was expressed equally in both species on cotton, Bt-mMnSOD messenger RNA was up-regulated in MEAM 1 on tobacco. Consistently, enzymatic activity assays of CuZnSOD and MnSOD demonstrated that CuZnSOD might play an important protective role against oxidative stress in Asia II 3, whereas MnSOD activation was critical for MEAM1 whiteflies during host adaptation. Taken together, our results suggest that the successful invasion ofMEAM 1 is correlated with its constitutive high activity of CuZnSOD and inducible expression of MnSOD under stress conditions.展开更多
To investigate whether the proton-accepting ability of imidazole in Cu,Zn-superoxide dismutase （SOD） was possibly modulated by Zn（Ⅱ） or not, the proton affinity （Ap） of N^3 in imidazole group was calculated by ...To investigate whether the proton-accepting ability of imidazole in Cu,Zn-superoxide dismutase （SOD） was possibly modulated by Zn（Ⅱ） or not, the proton affinity （Ap） of N^3 in imidazole group was calculated by density functional theory （DFT） with B3LYP functional. It was found that Zn（Ⅱ） attenuates the Ap, because of its electron-withdrawing effect, while the three ligands connected with Zn（Ⅱ） （residues of two His and one Asp） exert an opposite effect, owing to their electron-donating ability. This finding suggested that the three ligands should play a role in the normal function of Cu,Zn-SOD and should be taken into consideration in the future study.展开更多
基金overseas returned scholars’ starting working grants to AN Zhi-gang (Northeast Forestry University)
文摘The expression of a rice Cu/Zn superoxide dismutase （Cu/Zn-SOD） in Saccharomyces cerevisiae regulated by GAPDH promoter, involved in the inhibition of endogenous Glutathione （GSH） synthesis, and the competitive expression was detected by constructing the expression vector transferred Cu/Zn-SOD gene into wild-type S. cerevisiae. Transcription and expression of the Cu/Zn-SOD gene in S. cerevisiawere were confirmed by northern blot and SDS-PAGE, respectively, and activity of the Cu/Zn-SOD from crude extracts was enzymatically detected based on the effect of nitroblue tetrazolium （NBT） after running a native polyacrylamide gel. The GSH synthesis was also tested by DTNB （5, 5＇-Dithiobis （2-nitrobenzoic acid）） method. Results showed that GSH synthesis was evidently suppressed by the expression of Cu/Zn-SOD gene in both control and heat shock strains. It implied that the expression of the Cu/Zn-SOD gene in S. cerevisiae has more potential facility in response to oxidative exposure than that of endogenous GSH, although Cu/Zn-SOD and GSH were both contributed to the function of oxygen radical oxidoreduction.
文摘AIM: To investigate the effects of hydrogen(H2) on Cu, Zn superoxide dismutase(SOD1) activation in a rat model of corneal alkali burn. METHODS: In each rat, one cornea was subjected to alkali exposure. Physiological saline(saline group) or H2-dissolved saline(H2 group) was instilled continuously on the cornea for 5 min before and after alkali exposure. Inflammatory cells, neovascularization, and cytoplasmic SOD1 levels were evaluated immunohistochemically in enucleated eyes from both groups. Three-dimensional ultrastructural tissue changes in the eyes were analyzed using low-vacuum scanning electron microscopy.RESULTS: The numbers of both inflammatory and vascular endothelial cells were significantly reduced in the corneas of the H2 group(P<0.01). Furthermore, H2 treatment increased both cytoplasmic SOD1 levels(P<0.01) and activity in corneal epithelial cells(P<0.01). Notably, the SOD1 activity level in the H2 group was approximately 2.5-fold greater than that in the saline group.CONCLUSION: H2 treatment suppresses inflammation and neovascularization in the injured cornea and indirectly suppresses oxidative insult to the cornea by upregulating the SOD1 enzyme protein level and activity.
文摘Cu/Zn-superoxide dismutase (Cu/Zn-SOD) is an enzyme that is ubiquitously present in the cytoplasm and causes dismutation of superoxide radicals, therefore Cu/Zn-SOD is primarily used as an antioxidant marker. Levels of Cu/Zn-SOD are higher in the serum of hemodialysis patients than in serum of healthy volunteers. The increase of serum Cu/Zn-SOD levels is related to the decrease of kidney function with aging and arteriosclerosis in hemodialysis patients. Moreover, infection, vascular puncture, and hemostasis may be related to the increase in serum Cu/Zn-SOD levels. As it is associated with numerous factors in hemodialysis patients, Cu/Zn-SOD may serve as a complex marker for arteriosclerosis, vascular, and inflammatory conditions. It is important to investigate various agents that decrease serum Cu/Zn-SOD levels to improve the life-span of hemodialysis patients.
基金Supported by University Grants Commission,New Delhi(F.403(M/S)/2009(SA-Ⅲ/MANF)
文摘Objective:To determine the activity of superoxide dismutase(SOD) in the male and female haematophagous caprine worms,Haemonchus contortus infecting Capra hircus,and their E/S products and also to analyse the effect of Haemonchus infection on the level of host SOD.Methods:The SOD activity was analysed by using the pyrogallol autoxidation assay and non-denaturing polyacrylamide gel electrophoresis followed by specific enzyme staining by riboflavin-nitroblue tetrazolium method.Results:The adult females were found to have higher enzyme activity than the male worms.Appreciable amount of SOD activity was also detected in the worm culture medium and female worms secreted more SOD in comparison to the male parasites.The SOD activity was negatively correlated to the worm burden.Statistically significant decrease in SOD activity(P<0.05) was observed in the heavily infected host tissue in comparison to the control non-infected host tissue.SOD profile of the crude extracts of both the sexes revealed polymorphism and a fast migrating activity band being characteristic of E/S products.The SOD activities were found highly sensitive to potassium cyanide indicating the Cu/Zn form of SOD.Conclusions:Haemonchus contortus is a key model parasite for drug and vaccine discovery.The presences of SOD activity in appreciable amount in the parasite as well as its E/S products indicate that it has a well-developed active antioxidant system to protect itself from the host immune attack.SOD could be the target for vaccine development which is the need of the hour as mass drug administration for parasite control has resulted in anthelmintic resistance across the globe and threatens the viability of sheep and goat industry in many regions of the world.The infection with Haemonchus causes a drastic reduction in SOD activity of the host tissue thus effecting its protective potential.One characteristic SOD band was found in the females which was not present in any other preparations and thus could be exploited for further studies on diagnostic/control measures.
基金the National Natural Science Foundation of China(Nos.61571426,61671435,81630053)Beijing Natural Science Foundation(No.4161003)for financial support
文摘Superoxide dismutase(SOD) is an important antioxidant enzyme in the body. SOD has special physiological activity and is the primary substance for scavenging free radicals in living organisms.However, the expensive and complex extraction processes, low SOD yield, as well as difficult to store at room temperature have seriously hindered its application pace. Herein, the enzyme mimetic function of Mn-doped ZnS quantum dots(QDs) was discovered. The improved Marklund and McCord method both showed that Mn-doped ZnS QDs possess intrinsic SOD-like activity. The effects of temperature and pH on the mimetic enzyme activity of Mn-doped ZnS QDs have been investigated compared with SOD enzymes.The low cost and easy to synthesize white Mn-doped ZnS QDs with good biocompatibility are expected to be used as a new type of SOD nanozymes in the biology-relevant fields.
基金Acknowledgments Financial support for this study was provided by the National Natural Science Foundation of China （Projects 31071686, 31171848）, the Program for New Century Excellent Talents in University （NCET-12-0483） and the Specialized Research Fund for the Doctoral Program of Higher Education （Project 20120101110077）.
文摘Superoxide dismutases （SODs） are a group of important antioxidant defense enzymes. In this study, a putative extracellular Cu/Zn superoxide dismutase （ecCuZnSOD） complementary DNA was cloned and characterized from the whitefly, Bemisia tabaci. Quantitative polymerase chain reaction analysis showed that the expression level of BtecCuZnSOD was more than 10-fold higher in the invasive Middle East Asia Minor 1 （MEAM1） than in the native Asia II 3 species of the B. tabaci species complex. After exposure to low temperature （4 ℃）, the expression of Bt-ecCuZnSOD gene was significantly up-regulated in MEAM1 but not in Asia II 3. Furthermore, the expression level ofB. tabaci intracellular CuZnSOD （Bt-icCuZnSOD）, Bt-ecCuZnSOD and mitochondrial MnSOD （Bt-mMnSOD） was compared after transferring MEAM1 and Asia II 3 whiteflies from favorable （cotton） to unfavorable host plants （tobacco）. On cotton, both CuZnSOD genes were expressed at a higher level in MEAM1 compared with Asia II 3. Interestingly, after transferring onto tobacco, the expression of Bt-ecCuZnSOD was significantly induced in Asia II 3 but not in MEAM1. On the other hand, while Bt-mMnSOD was expressed equally in both species on cotton, Bt-mMnSOD messenger RNA was up-regulated in MEAM 1 on tobacco. Consistently, enzymatic activity assays of CuZnSOD and MnSOD demonstrated that CuZnSOD might play an important protective role against oxidative stress in Asia II 3, whereas MnSOD activation was critical for MEAM1 whiteflies during host adaptation. Taken together, our results suggest that the successful invasion ofMEAM 1 is correlated with its constitutive high activity of CuZnSOD and inducible expression of MnSOD under stress conditions.
基金Project supported by the National Basic Research Program of China （No.2003CB 114400） and the National Natural Science Foundation of China （Nos. 30100035 and 30570383）.
文摘To investigate whether the proton-accepting ability of imidazole in Cu,Zn-superoxide dismutase （SOD） was possibly modulated by Zn（Ⅱ） or not, the proton affinity （Ap） of N^3 in imidazole group was calculated by density functional theory （DFT） with B3LYP functional. It was found that Zn（Ⅱ） attenuates the Ap, because of its electron-withdrawing effect, while the three ligands connected with Zn（Ⅱ） （residues of two His and one Asp） exert an opposite effect, owing to their electron-donating ability. This finding suggested that the three ligands should play a role in the normal function of Cu,Zn-SOD and should be taken into consideration in the future study.
