家蚕质多角体病毒片段IV的全序列测定

在随机引物建库的基础上,通过交叉设计引物及加单链DNA接头,应用RT-PCR技术克隆的家蚕质多角体病毒dsRNA片段Ⅳ的全长cDNA,并测定了它的全序列。该片段长3,262bp,含有一个完整的开放讯码框,编码一个长1,058氨基酸的成熟多肽。序列分析表明,该片段与日本BmCPV片段Ⅳ的核苷酸序列同源性为89％,氨基酸序列同源性为95％。     

伊蚊浓核病毒三维结构的比较分析

细小病毒是目前已知的结构最小的病毒, 其宿主范围很广. 利用冷冻电镜和三维重构技术获得了伊蚊浓核病毒1.2 nm分辨率下的三维结构, 并利用计算机生物信息处理技术和氨基酸序列比对技术比较了该病毒和其他细小病毒的结构和序列的异同. 尽管均属于浓核病毒亚科, 但是无论从衣壳结构还是其蛋白质的氨基酸序列上, 伊蚊浓核病毒和其他昆虫的细小病毒都有很大差异. 相比之下, 伊蚊浓核病毒和人类B19细小病毒的衣壳蛋白相似性较大, 两者的结构蛋白和非结构蛋白一致性也高于伊蚊浓核病毒与其他昆虫的细小病毒的一致性. 此结果表明: 伊蚊浓核病毒和人类B19细小病毒有着密切关系, 前者可能来源于B19病毒的较近期变种.     

中蜂囊状幼虫病病毒的三维结构

提取纯化中蜂囊状幼虫病病毒(CSBV)的RNA,通过RT-PCR扩增获得1069bp的DNA片段,将其克隆到pGEM-T Easy载体上.测序分析表明,该段基因序列与意蜂囊状幼虫病病毒(SBV)基因序列的同源性为87.6%,与之对应的氨基酸序列的一致性高达94.6%,说明CSBV是与SBV十分相似而又不相同的病毒.在此基础上,应用冷冻电子显微镜与计算机三维重构方法测得病毒颗粒的三维结构,分辨率为2.5nm,其衣壳按T=1(p=3)的对称二十面体结构排列,表面光滑,有12个五邻体和132个孔洞.研究还发现,病毒内部的核酸是按5-3-2对称的二十面体结构排列,这种排列方式在细小RNA病毒中尚未见报道.     

严重急性呼吸综合征（SARS）病毒的形态及其形态发生机制

将SARS患者的咽拭子感染VeroE6细胞 ,用电子显微技术等对SARS病毒进行了研究。结果表明 ,新分离到的病毒粒子没带囊膜时直径大多约 5 0nm ,带有囊膜的直径约 10 0nm。通过RT PCR等证明 ,该病毒是新的冠状病毒。这些病毒可与SARS康复患者的血清呈强烈的阳性反应 ,表明此新的冠状病毒是引起SARS的主要病原。文中还对病毒的发生机制和细胞中的分布进行了探讨。     

Three-dimensional structure of the Chinese Sacbrood bee virus

The RNA of Chinese Sacbrood Bee Virus (CSBV) was purified and used as template to obtain a 1096 bp cDNA fragment by RT-PCR amplification. This DNA fragment was cloned into pGEM-T Easy Vector for sequencing. Analyses of the sequenced CSBV RNA fragment revealed a nucleotide sequence homology of 87.6% and a deduced amino-acid sequence homology of 94.6% with that of the Sacbrood Virus (SBV), indicating that CSBV is a different but highly homologous virus of SBV. The three-dimensional (3D) structure of CSBV was determined at 2.5 nm resolution by using electron cryo-microscopy (cryoEM) and computer reconstruction methods. The 3-D structure showed that the capsid has aT = 1 (orP = 3) icosahedral capsid shell with a smooth surface. There were 12 pentons at its icosahedral vertices (5-fold axes) and 132 holes penetrating the shell. The 3-D structure also revealed densities corresponding to the CSBV genome, suggesting icosahedrally-ordered RNA organization, a novel feature not previously reported for any picornaviruses.     

伊蚊C6/36细胞浓核病毒蛋白衣壳三维结构的测定

利用冷冻电子显微技术和计算机图像三维重构方法获得伊蚊C6/36细胞浓核病毒蛋白衣壳的三维结构, 分辨率为1.4 nm. 结果显示C6/36 DNV蛋白衣壳的三角形剖分数T = 1, 在二十面体的每个面上有12个孔, 可能是DNA的通道, 每个五次轴上有一个柱状突起.     

乙型肝炎核心抗原C端154截短颗粒的三维结构

利用冷冻电子显微镜三维重构技术获得了分辨率为7.8?的乙型肝炎核心抗原于C端154aa处截短颗粒(HBcAg-154)的三维结构.结构显示,该颗粒主要由α螺旋组成,蛋白质折叠与核心抗原C端149截短颗粒(HBcAg-149)极其相似.而且二者内部均很难观察到RNA的电子密度,近乎是空的.导致该结果的原因可能是由于150~154aa的短肽仅含5个氨基酸,序列太短以致不能结合足够的RNA分子,可见核心蛋白C端的155~183aa区域对于颗粒的核酸包裹更为重要.     

Three-dimensional structure of the Chinese Sacbrood bee virus

The RNA of Chinese Sacbrood Bee Virus (CSBV) was purified and used as template to obtain a 1096 bp cDNA fragment by RT-PCR amplification. This DNA fragment was cloned into pGEM-T Easy Vector for sequencing. Analyses of the sequenced CSBV RNA fragment revealed a nucleotide sequence homology of 87.6% and a deduced amino-acid sequence homology of 94.6% with that of the Sacbrood Virus (SBV), indicating that CSBV is a different but highly homologous virus of SBV. The three-dimensional (3D) structure of CSBV was determined at 2.5 nm resolution by using electron cryo-microscopy (cryoEM) and computer reconstruction methods. The 3-D structure showed that the capsid has a T= 1 (or P= 3) icosahedral capsid shell with a smooth surface. There were 12 pentons at its icosahedral vertices (5-fold axes) and 132 holes penetrating the shell. The 3-D structure also revealed densities corresponding to the CSBV genome, suggesting icosahedrally-ordered RNA organization, a novel feature not previously reported for any picornavi     

家蚕质多角体病毒(BmCPV)基因组dsRNA片段V的全序列测定

质多角体病毒属于呼肠孤病毒科质多角体病毒属,代表种为家蚕质多角体病毒(Bombyx mori cytoplasmic polyhedrosis virus,BmCPV).质多角体病毒粒子为正二十面体,直径约60nm～80nm,正二十面体的十二个顶点均有管状突起.