Snake venoms,especially those from the two subfamilies,Crotalinae and Viperinae,contained a lot of serine proteases. They were responsible for the hemorrhage,shock,or disorder of blood coagulation after envenomation. ...Snake venoms,especially those from the two subfamilies,Crotalinae and Viperinae,contained a lot of serine proteases. They were responsible for the hemorrhage,shock,or disorder of blood coagulation after envenomation. They acted,by activating,inactivating,or other converting effects,on almost all the components of hemostatic and fibrinolytic systems. Their sequences were homologous to trypsin-kallikrein serine proteases. Variation of primary sequences out of active center results in the difference of substrate specificities and the further difference of biological and pharmacological activities. Because of their common and unique properties compared to their physiological corresponding factors,snake venom proteases are proved to be an excellent model for the study of protease substrate discriminating mechanism. Furthermore,they have found an important position both in basic research and application of hemostasis and thrombosis in clinic.展开更多
AIM： To analyze our Wilson disease patient cohort （n = 106） for alterations in the gene coding for MURR1. METHODS： Patients with an established diagnosis of Wilson disease but normal ceruloplasmin blood levels wer...AIM： To analyze our Wilson disease patient cohort （n = 106） for alterations in the gene coding for MURR1. METHODS： Patients with an established diagnosis of Wilson disease but normal ceruloplasmin blood levels were chosen for our study （n = 14）. Patients with two known disease-causing mutations in the ATPTB gene were not included. The three exons of the human MURR1 gene were sequenced after amplification of the genomic DNA by polymerase chain reaction. RESULTS： Our study did not reveal any mutations leading to an amino acid change in the MURR1 sequence of Wilson disease patients. A polymorphism at 472 bp of the coding sequence could be confirmed. CONCLUSION： The MURRI gene plays no role in the pathogenesis of Wilson disease patients with normal serum ceruloplasmin levels.展开更多
Objective.To study whether the abilities of hepatitis C virus(HCV)E2 gene immunization to induce humoral and cellular immune responses to E2 protein were affected by hepatitis B virus(HBV)preS gene when they were fuse...Objective.To study whether the abilities of hepatitis C virus(HCV)E2 gene immunization to induce humoral and cellular immune responses to E2 protein were affected by hepatitis B virus(HBV)preS gene when they were fused in DNA-immunized mice.Methods.Mice were immunized with E2,preS-E2(preS gene was upstream of E2 gene),and E2-preS(preS gene was downstream of E2 gene)gene by their eukaryotic expression vectors,respectively.The anti-E2 or anti-preS antibodies were detected using the E2 and preS antigens.The cellular immune response to E2 pro-tein in immunized mice was presented by its survival time after injecting SP2/O myeloma cells expressing HCV E2 protein into the abdominal cavity.Results. Chimeric E2 and preS gene immunization can induce mice to develop anti-preS and anti-E2 antibodies.The number of the mice developing anti-E2 antibody and the antibody titers in preS-E2 gene-injected group were higher than those in E2-preS gene-immunized group.However,the mice injected with E2 gene did not develop the detectable anti-E2 antibodies until 12 weeks after DNA immunization.After the mice was injected with target cells,the average survival time of the mice in the group immunized with E2 gene alone was longer than that of the group injected with E2 gene fused with HBV preS and was significantly longer than that of the control(P< 0.05).Conclusion.HBV preS might be a humoral enhancer that can affect the abilities of HCV E2 protein to in-duce immune responses in DNA-immunized mice.展开更多
AIM: We have previously demonstrated that hepatitis C virus (HCV) core protein is efficiently released into the culture medium in insect cells. The objective of this study is to characterize the HCV core secretion in ...AIM: We have previously demonstrated that hepatitis C virus (HCV) core protein is efficiently released into the culture medium in insect cells. The objective of this study is to characterize the HCV core secretion in insect cells. METHODS: We constructed recombinant baculoviruses expressing various-length of mutant core proteins, expressed these proteins in insect cells, and examined core protein secretion in insect cells. RESULTS: Only wild type core was efficiently released into the culture medium, although the protein expression level of wild type core was lower than those of other mutant core proteins. We found that the shorter form of the core construct expressed the higher level of protein. However, if more than 18 amino acids of the core were truncated at the C-terminus, core proteins were no longer secreted into the culture medium. Membrane flotation data show that the secreted core proteins are associated with the cellular membrane protein, indicating that HCV core is secreted as a membrane complex. CONCLUSION: The C-terminal 18 amino acids of HCV core were crucial for core secretion into the culture media. Since HCV replication occurs on lipid raft membrane structure, these results suggest that HCV may utilize a unique core release mechanism to escape immune surveillance, thereby potentially representing the feature of HCV morphogenesis.展开更多
Objective: To study the physical and chemical properties of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China.Methods:The arginine ester hydrolase(AEH) was isolated fr...Objective: To study the physical and chemical properties of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China.Methods:The arginine ester hydrolase(AEH) was isolated from the venom of Chinese Trimeresurus mucrosqumatus by a combination of ion-exchange chromatography on DEAE-Sephadex A-50, CM-Sepharose Cl-6B and gel filtration on Sephadex G-100.Results: The purified protein named TM-AEH,a glycoprotein with carbohydrate content of 0.5% neutral hexose and 0.75% sialic acid,a relative molecular mass of 29.0 kDa,and an isoelectric point(pI) of 5.2. It shares with an extinction coefficient(E 0.1%/cm) of 1.332 at 280 nm,consisted of 225 amino acid residues,and migrated as a band under reduced or non-reduced condition in basic PAGE.TM-AEH was a highly thermostable protein and was stable to pH changes between 5 and 9.The optimum temperature and optimum pH were 55℃ and 8.4 for its catalytic activity respectively,which was inhibited by Fe 3+ and Cu 2+.Conclusion:This protein can exhibit higher BAEE-hydrolysing activity and fibrinogenolytic activity as compared to that of whole venom.展开更多
Recently, a novel porcine circovirus-like virus P1 with a circular DNA genome of 0.648 kb was identified. P1 antigen was detected both in vitro and in vivo by synthetic peptide-derived polyclonal antibody-based immuno...Recently, a novel porcine circovirus-like virus P1 with a circular DNA genome of 0.648 kb was identified. P1 antigen was detected both in vitro and in vivo by synthetic peptide-derived polyclonal antibody-based immunochemistry. The designed peptides were synthesized by solid-phase technique, purified by high performance liquid chromatography, coupled to Keyhole limpet hemocyanin, and injected into rabbits to prepare polyclonal antibody. The emergence of positive cells revealed that synthetic peptide could elicit antibodies against P1 and viral protein could be synthesized. The polyclonal peptide antibodies described here was successfully applied to immunochemical staining and proved helpful in diagnosing P1.展开更多
文摘Snake venoms,especially those from the two subfamilies,Crotalinae and Viperinae,contained a lot of serine proteases. They were responsible for the hemorrhage,shock,or disorder of blood coagulation after envenomation. They acted,by activating,inactivating,or other converting effects,on almost all the components of hemostatic and fibrinolytic systems. Their sequences were homologous to trypsin-kallikrein serine proteases. Variation of primary sequences out of active center results in the difference of substrate specificities and the further difference of biological and pharmacological activities. Because of their common and unique properties compared to their physiological corresponding factors,snake venom proteases are proved to be an excellent model for the study of protease substrate discriminating mechanism. Furthermore,they have found an important position both in basic research and application of hemostasis and thrombosis in clinic.
文摘AIM： To analyze our Wilson disease patient cohort （n = 106） for alterations in the gene coding for MURR1. METHODS： Patients with an established diagnosis of Wilson disease but normal ceruloplasmin blood levels were chosen for our study （n = 14）. Patients with two known disease-causing mutations in the ATPTB gene were not included. The three exons of the human MURR1 gene were sequenced after amplification of the genomic DNA by polymerase chain reaction. RESULTS： Our study did not reveal any mutations leading to an amino acid change in the MURR1 sequence of Wilson disease patients. A polymorphism at 472 bp of the coding sequence could be confirmed. CONCLUSION： The MURRI gene plays no role in the pathogenesis of Wilson disease patients with normal serum ceruloplasmin levels.
文摘Objective.To study whether the abilities of hepatitis C virus(HCV)E2 gene immunization to induce humoral and cellular immune responses to E2 protein were affected by hepatitis B virus(HBV)preS gene when they were fused in DNA-immunized mice.Methods.Mice were immunized with E2,preS-E2(preS gene was upstream of E2 gene),and E2-preS(preS gene was downstream of E2 gene)gene by their eukaryotic expression vectors,respectively.The anti-E2 or anti-preS antibodies were detected using the E2 and preS antigens.The cellular immune response to E2 pro-tein in immunized mice was presented by its survival time after injecting SP2/O myeloma cells expressing HCV E2 protein into the abdominal cavity.Results. Chimeric E2 and preS gene immunization can induce mice to develop anti-preS and anti-E2 antibodies.The number of the mice developing anti-E2 antibody and the antibody titers in preS-E2 gene-injected group were higher than those in E2-preS gene-immunized group.However,the mice injected with E2 gene did not develop the detectable anti-E2 antibodies until 12 weeks after DNA immunization.After the mice was injected with target cells,the average survival time of the mice in the group immunized with E2 gene alone was longer than that of the group injected with E2 gene fused with HBV preS and was significantly longer than that of the control(P< 0.05).Conclusion.HBV preS might be a humoral enhancer that can affect the abilities of HCV E2 protein to in-duce immune responses in DNA-immunized mice.
基金Supported by a grant from the Korean Ministry of Science and Technology (Korean Systems Biology Research Grant, M1-0309-06-0002) partly by the research grant from Hallym University, Korea Co-first-authors: Kyu-Jin Park
文摘AIM: We have previously demonstrated that hepatitis C virus (HCV) core protein is efficiently released into the culture medium in insect cells. The objective of this study is to characterize the HCV core secretion in insect cells. METHODS: We constructed recombinant baculoviruses expressing various-length of mutant core proteins, expressed these proteins in insect cells, and examined core protein secretion in insect cells. RESULTS: Only wild type core was efficiently released into the culture medium, although the protein expression level of wild type core was lower than those of other mutant core proteins. We found that the shorter form of the core construct expressed the higher level of protein. However, if more than 18 amino acids of the core were truncated at the C-terminus, core proteins were no longer secreted into the culture medium. Membrane flotation data show that the secreted core proteins are associated with the cellular membrane protein, indicating that HCV core is secreted as a membrane complex. CONCLUSION: The C-terminal 18 amino acids of HCV core were crucial for core secretion into the culture media. Since HCV replication occurs on lipid raft membrane structure, these results suggest that HCV may utilize a unique core release mechanism to escape immune surveillance, thereby potentially representing the feature of HCV morphogenesis.
文摘Objective: To study the physical and chemical properties of an arginine ester hydrolase from the venom of Trimeresurus mucrosqumatus in Hunan province of China.Methods:The arginine ester hydrolase(AEH) was isolated from the venom of Chinese Trimeresurus mucrosqumatus by a combination of ion-exchange chromatography on DEAE-Sephadex A-50, CM-Sepharose Cl-6B and gel filtration on Sephadex G-100.Results: The purified protein named TM-AEH,a glycoprotein with carbohydrate content of 0.5% neutral hexose and 0.75% sialic acid,a relative molecular mass of 29.0 kDa,and an isoelectric point(pI) of 5.2. It shares with an extinction coefficient(E 0.1%/cm) of 1.332 at 280 nm,consisted of 225 amino acid residues,and migrated as a band under reduced or non-reduced condition in basic PAGE.TM-AEH was a highly thermostable protein and was stable to pH changes between 5 and 9.The optimum temperature and optimum pH were 55℃ and 8.4 for its catalytic activity respectively,which was inhibited by Fe 3+ and Cu 2+.Conclusion:This protein can exhibit higher BAEE-hydrolysing activity and fibrinogenolytic activity as compared to that of whole venom.
基金Supported by National Natural Science Foundation of China(31272574,30972184)
文摘Recently, a novel porcine circovirus-like virus P1 with a circular DNA genome of 0.648 kb was identified. P1 antigen was detected both in vitro and in vivo by synthetic peptide-derived polyclonal antibody-based immunochemistry. The designed peptides were synthesized by solid-phase technique, purified by high performance liquid chromatography, coupled to Keyhole limpet hemocyanin, and injected into rabbits to prepare polyclonal antibody. The emergence of positive cells revealed that synthetic peptide could elicit antibodies against P1 and viral protein could be synthesized. The polyclonal peptide antibodies described here was successfully applied to immunochemical staining and proved helpful in diagnosing P1.
