According to the published gene sequence of the major surface antigen (P30) of Toxoplasma gondii, a pair of primers were designed and synthesized. Using polymerase chain reaction (PCR), the coding sequences of P30 gen...According to the published gene sequence of the major surface antigen (P30) of Toxoplasma gondii, a pair of primers were designed and synthesized. Using polymerase chain reaction (PCR), the coding sequences of P30 gene were amplified from a Chinese strain of T. gondii, The amplified gene fragment and plasmid pB220 were digested with EcoRI and BamHI and then ligated. The inserted gene fragment was sequenced by the chain termination method, the reading reveals that nucleotide sequence determined was the same as the P30 sequecne of RH strain pubilished by Burg (1988), except that one base was changed. The recombinant plasmid containing P30 gene was transformed to E. coli DH5α.After temperature inducing culture, the total cellular proteins were analysed by SDS-PAGE and Western blot. The results show that the p30 gene cloned into the plasmid could express in E. coli, and the expression product had immunogenicity.展开更多
To explore a novel strategy for antisense gene therapy of cancer,the coding sequence of hum an proliferating cell nuclear antigen(PCNA) c DNA was reversely inserted into the eukaryotic vector p L XSN by molecular cl...To explore a novel strategy for antisense gene therapy of cancer,the coding sequence of hum an proliferating cell nuclear antigen(PCNA) c DNA was reversely inserted into the eukaryotic vector p L XSN by molecular cloning techniques and transferred into bladder cancer EJcells with li- posome. The PCNA expression in transferred cells was dynamically detected by immunofluo- rescence and RT- PCR techniques. Changes of proliferation activities of cancer cells were assayed by MTT colorim etric and cloning formation m ethods.In the experiment,the antisense eukaryotic vector was successfully constructed and nam ed as p L APSN.After transfection with it for1- 7 days,PCNA protein and m RNA levels in cancer cells were blocked by16 .74 % - 84 .2 1% (P< 0 .0 5 ) and2 3.2 7% - 86 .15 % (P<0 .0 5 ) respectively.The proliferation activities of transferred cells were inhibited by 2 7.91% - 6 2 .0 7% (P<0 .0 1) ,with cloning formation abilities being de- creased by 5 0 .81% (P<0 .0 1) . Itwas concluded that the in vitro proliferation activities of cancer cells could be effectively inhibited by blocking PCNA expression with antisense technique,which could serve as an ideal strategy for gene therapy of bladder cancer.展开更多
OBJECTIVE: To investigate the role of the 25 kD hepatitis B e antigen (HBeAg) precursor that only exist inside hepatocytes and study its effect on the pathopoiesis of hepatitis B and QIAGEN expression and purification...OBJECTIVE: To investigate the role of the 25 kD hepatitis B e antigen (HBeAg) precursor that only exist inside hepatocytes and study its effect on the pathopoiesis of hepatitis B and QIAGEN expression and purification system. METHODS: Hepatitis B virus (HBV) preC/C gene for the 25 kD HBeAg precursor was cloned into the expression vector pQE30 and the 25 kD HBeAg precursor was expressed in Escherichia coli (E. coli) and purified. Its antigenicity for 21 kD mature HBeAg was tested by western blot analysis. RESULTS: Cloned fragments in the expression vector were sequenced and verified to be homogeneous with that of HBV (ayw subtype). Expression of the HBeAg precursor in E. coli under the transcriptional regulation of T5 promoter yielded a soluble cytosolic protein with an apparent molecular mass of 25 kD. Recombinant HBeAg precursor exhibited identical potencies with 21 kD mature HBeAg that reacted with anti-HBeAg antibodies. The purification rate of the expressed HBeAg precursor was up to 89.6% and the yield of purified HBeAg precursor from this procedure was 2.4 mg/L. CONCLUSION: 25 kD HBeAg precursor exhibited biological activity and might play an important role in pathopoiesis of hepatitis B.展开更多
[目的 ]扩增和克隆猪带绦虫囊尾蚴 Ag B基因的 c DNA编码区。 [方法 ]提取猪囊尾蚴总 RNA中 ,利用 RT- PCR技术扩增出 Ag B基因 c DNA编码区 ,然后将其克隆到载体 p UC118中进行序列分析。 [结果 ]PCR反应产物为单一条带 ,大小为 2 .6 k...[目的 ]扩增和克隆猪带绦虫囊尾蚴 Ag B基因的 c DNA编码区。 [方法 ]提取猪囊尾蚴总 RNA中 ,利用 RT- PCR技术扩增出 Ag B基因 c DNA编码区 ,然后将其克隆到载体 p UC118中进行序列分析。 [结果 ]PCR反应产物为单一条带 ,大小为 2 .6 kb。测序结果与澳大利亚株猪囊尾蚴 Ag B序列有 99.8%的同源性 ,二者的氨基酸序列有 99.3%的同源性。 [结论 ]成功地克隆了猪囊尾蚴 Ag B基因 c DNA编码区。展开更多
目的 构建并克隆屋尘螨抗原 Der p2基因 ,在大肠杆菌中初步表达 .方法 根据已发表的 Der p2基因 ,人工设计合成一系列基因片段 ,经单链扩增后连接成完整的 Der p2基因 ;将该基因克隆入表达载体 p Pro EX HTb中 ,测序并进行初步表达 ....目的 构建并克隆屋尘螨抗原 Der p2基因 ,在大肠杆菌中初步表达 .方法 根据已发表的 Der p2基因 ,人工设计合成一系列基因片段 ,经单链扩增后连接成完整的 Der p2基因 ;将该基因克隆入表达载体 p Pro EX HTb中 ,测序并进行初步表达 .结果 利用所设计的结构制备了完整的 Der p2基因 ,以大肠杆菌为宿主在 IPTG的诱导下获得初步表达 ,该外源蛋白 Mr约为 17× 10 3,占总蛋白量的 2 0 % .结论 所构建的 Der展开更多
文摘According to the published gene sequence of the major surface antigen (P30) of Toxoplasma gondii, a pair of primers were designed and synthesized. Using polymerase chain reaction (PCR), the coding sequences of P30 gene were amplified from a Chinese strain of T. gondii, The amplified gene fragment and plasmid pB220 were digested with EcoRI and BamHI and then ligated. The inserted gene fragment was sequenced by the chain termination method, the reading reveals that nucleotide sequence determined was the same as the P30 sequecne of RH strain pubilished by Burg (1988), except that one base was changed. The recombinant plasmid containing P30 gene was transformed to E. coli DH5α.After temperature inducing culture, the total cellular proteins were analysed by SDS-PAGE and Western blot. The results show that the p30 gene cloned into the plasmid could express in E. coli, and the expression product had immunogenicity.
基金This studywassupported by a grant from the NationalNatural Sciences Foundation ofChina(No. 39770 739)
文摘To explore a novel strategy for antisense gene therapy of cancer,the coding sequence of hum an proliferating cell nuclear antigen(PCNA) c DNA was reversely inserted into the eukaryotic vector p L XSN by molecular cloning techniques and transferred into bladder cancer EJcells with li- posome. The PCNA expression in transferred cells was dynamically detected by immunofluo- rescence and RT- PCR techniques. Changes of proliferation activities of cancer cells were assayed by MTT colorim etric and cloning formation m ethods.In the experiment,the antisense eukaryotic vector was successfully constructed and nam ed as p L APSN.After transfection with it for1- 7 days,PCNA protein and m RNA levels in cancer cells were blocked by16 .74 % - 84 .2 1% (P< 0 .0 5 ) and2 3.2 7% - 86 .15 % (P<0 .0 5 ) respectively.The proliferation activities of transferred cells were inhibited by 2 7.91% - 6 2 .0 7% (P<0 .0 1) ,with cloning formation abilities being de- creased by 5 0 .81% (P<0 .0 1) . Itwas concluded that the in vitro proliferation activities of cancer cells could be effectively inhibited by blocking PCNA expression with antisense technique,which could serve as an ideal strategy for gene therapy of bladder cancer.
基金TheworkwassupportedbygrantsfromtheNationalNaturalScienceFoundationofChina (No 3 963 0 2 80 )
文摘OBJECTIVE: To investigate the role of the 25 kD hepatitis B e antigen (HBeAg) precursor that only exist inside hepatocytes and study its effect on the pathopoiesis of hepatitis B and QIAGEN expression and purification system. METHODS: Hepatitis B virus (HBV) preC/C gene for the 25 kD HBeAg precursor was cloned into the expression vector pQE30 and the 25 kD HBeAg precursor was expressed in Escherichia coli (E. coli) and purified. Its antigenicity for 21 kD mature HBeAg was tested by western blot analysis. RESULTS: Cloned fragments in the expression vector were sequenced and verified to be homogeneous with that of HBV (ayw subtype). Expression of the HBeAg precursor in E. coli under the transcriptional regulation of T5 promoter yielded a soluble cytosolic protein with an apparent molecular mass of 25 kD. Recombinant HBeAg precursor exhibited identical potencies with 21 kD mature HBeAg that reacted with anti-HBeAg antibodies. The purification rate of the expressed HBeAg precursor was up to 89.6% and the yield of purified HBeAg precursor from this procedure was 2.4 mg/L. CONCLUSION: 25 kD HBeAg precursor exhibited biological activity and might play an important role in pathopoiesis of hepatitis B.
文摘[目的 ]扩增和克隆猪带绦虫囊尾蚴 Ag B基因的 c DNA编码区。 [方法 ]提取猪囊尾蚴总 RNA中 ,利用 RT- PCR技术扩增出 Ag B基因 c DNA编码区 ,然后将其克隆到载体 p UC118中进行序列分析。 [结果 ]PCR反应产物为单一条带 ,大小为 2 .6 kb。测序结果与澳大利亚株猪囊尾蚴 Ag B序列有 99.8%的同源性 ,二者的氨基酸序列有 99.3%的同源性。 [结论 ]成功地克隆了猪囊尾蚴 Ag B基因 c DNA编码区。
文摘目的 构建并克隆屋尘螨抗原 Der p2基因 ,在大肠杆菌中初步表达 .方法 根据已发表的 Der p2基因 ,人工设计合成一系列基因片段 ,经单链扩增后连接成完整的 Der p2基因 ;将该基因克隆入表达载体 p Pro EX HTb中 ,测序并进行初步表达 .结果 利用所设计的结构制备了完整的 Der p2基因 ,以大肠杆菌为宿主在 IPTG的诱导下获得初步表达 ,该外源蛋白 Mr约为 17× 10 3,占总蛋白量的 2 0 % .结论 所构建的 Der
