戊型肝炎病毒(Hepatitis E virus,HEV)是造成急性肝炎最常见的原因之一。HEV基因组由5′非编码区、3个开放阅读框(ORF1、ORF2、ORF3)和3′非编码区组成,仅在HEV-1中发现了ORF4,并与ORF1重叠。各种编码蛋白在HEV的复制和感染中发挥着不...戊型肝炎病毒(Hepatitis E virus,HEV)是造成急性肝炎最常见的原因之一。HEV基因组由5′非编码区、3个开放阅读框(ORF1、ORF2、ORF3)和3′非编码区组成,仅在HEV-1中发现了ORF4,并与ORF1重叠。各种编码蛋白在HEV的复制和感染中发挥着不同的作用,而HEV的复制是由ORF1编码的RNA依赖性RNA聚合酶(RNA-dependent RNA polymerase,RdRp)所介导的。HEV RdRp是由多个蛋白亚基组成的复合酶,具有7个保守基序,这些保守基序在RNA合成过程中发挥核苷酸识别、合成、延伸、修饰和稳定等作用,保证了RdRp的功能,在HEV的复制和转录中起到关键作用。因此,以RdRp作为抗HEV药物作用靶点的治疗方案具有很好的应用前景,是目前药物开发的一种主流思路。目前,已发现利巴韦林、索非布韦、2′-C-甲基胞苷(2CMC)等核苷类RdRp抑制剂和锌、GPC-N114等非核苷类RdRp抑制剂对HEV有较强的抑制作用,可作为潜在的抗HEV药物进行深入研究。笔者对HEV编码蛋白和HEV RdRp的结构与功能进行阐述,总结目前发现的对HEV有抑制作用的RdRp抑制剂,以期为HEV的药物开发提供一种新的思路。展开更多
NADP(H) dependent retinol dehydrogenase/reductase (NRDR) was an important retinoic acid synthase, which was first purified from rabbit liver in 1997. In order to study the function of the NRDR gene,the full length cDN...NADP(H) dependent retinol dehydrogenase/reductase (NRDR) was an important retinoic acid synthase, which was first purified from rabbit liver in 1997. In order to study the function of the NRDR gene,the full length cDNA of bovine NRDR was cloned. According to the conserved sequences of human, mouse and rabbit NRDR cDNA, a pair of primers was designed to amplify a 294 bp DNA fragment of bovine liver NRDR, and then the full length of NRDR cDNA (AF487454) was cloned by using 3′ RACE and 5′ RACE. All the cloned NRDR proteins consist of 260 amino acid residues and showed high identity among them. The tri peptide of human, mouse and rabbit NRDR C end was SRL and that of bovine NRDR C end was SHL, but both were considered to be peroxisomal target signal 1 (PTS1). RT PCR demonstrated that NRDR gene was expressed in liver, heart, lung, kidney, stomach and intestine, and was not found in pancreas, muscle, artery and skin. The full length bovine NRDR cDNA has been successfully cloned and the sequence was analyzed. It provided a reliable foundation to investigate the biological function of this protein.展开更多
西尼罗病毒(West Nile virus,WNV)非结构蛋白NS5是病毒基因组复制的关键蛋白.以病毒全长cDNA克隆为模板,PCR扩增获得NS5的RNA依赖的RNA聚合酶(RdRp)活性区(NS5pol)及该蛋白完整的编码序列(NS5F),分别克隆于原核表达载体pET-28a并转化至...西尼罗病毒(West Nile virus,WNV)非结构蛋白NS5是病毒基因组复制的关键蛋白.以病毒全长cDNA克隆为模板,PCR扩增获得NS5的RNA依赖的RNA聚合酶(RdRp)活性区(NS5pol)及该蛋白完整的编码序列(NS5F),分别克隆于原核表达载体pET-28a并转化至大肠杆菌E.coli BL21(DE3)中诱导表达.表达的可溶性重组蛋白经Ni柱亲和层析纯化后进行SDS-PAGE和Western印迹鉴定.结果显示,二者均为病毒特异蛋白,且纯度均在90%以上.进一步的体外RdRp分析及EMSA的结果表明,NS5pol和NSF5均有较高的RdRp活性,且该活性具有RNA模板序列和二级结构的特异性.获得的具有RdRp活性的NS5pol和NS5F为西尼罗病毒基因组复制相关元件的研究奠定了基础.展开更多
文摘NADP(H) dependent retinol dehydrogenase/reductase (NRDR) was an important retinoic acid synthase, which was first purified from rabbit liver in 1997. In order to study the function of the NRDR gene,the full length cDNA of bovine NRDR was cloned. According to the conserved sequences of human, mouse and rabbit NRDR cDNA, a pair of primers was designed to amplify a 294 bp DNA fragment of bovine liver NRDR, and then the full length of NRDR cDNA (AF487454) was cloned by using 3′ RACE and 5′ RACE. All the cloned NRDR proteins consist of 260 amino acid residues and showed high identity among them. The tri peptide of human, mouse and rabbit NRDR C end was SRL and that of bovine NRDR C end was SHL, but both were considered to be peroxisomal target signal 1 (PTS1). RT PCR demonstrated that NRDR gene was expressed in liver, heart, lung, kidney, stomach and intestine, and was not found in pancreas, muscle, artery and skin. The full length bovine NRDR cDNA has been successfully cloned and the sequence was analyzed. It provided a reliable foundation to investigate the biological function of this protein.
文摘西尼罗病毒(West Nile virus,WNV)非结构蛋白NS5是病毒基因组复制的关键蛋白.以病毒全长cDNA克隆为模板,PCR扩增获得NS5的RNA依赖的RNA聚合酶(RdRp)活性区(NS5pol)及该蛋白完整的编码序列(NS5F),分别克隆于原核表达载体pET-28a并转化至大肠杆菌E.coli BL21(DE3)中诱导表达.表达的可溶性重组蛋白经Ni柱亲和层析纯化后进行SDS-PAGE和Western印迹鉴定.结果显示,二者均为病毒特异蛋白,且纯度均在90%以上.进一步的体外RdRp分析及EMSA的结果表明,NS5pol和NSF5均有较高的RdRp活性,且该活性具有RNA模板序列和二级结构的特异性.获得的具有RdRp活性的NS5pol和NS5F为西尼罗病毒基因组复制相关元件的研究奠定了基础.
