SARS冠状病毒的基因组结构与药物治疗

介绍了SAPS冠状病毒的基因组结构及其作用机制的最新研究进展，探讨了抗SARS病毒药物的研制。     

对SARS制定科学术语的意见

建议将现称的萨斯(SARS)改称传染性冠状病毒肺炎。     

Dissection of SARS Coronavirus Spike Protein into Discrete Folded Fragments

Introduction Severe acute respiratory syndrome coronavirus (SARS-CoV), which is the causative agent of the atypical pneumonia, was first identified in the fall of 2002 to be a previously unknown member of the family of coronaviruses[1]. The rapid transmis…     

The outbreak pattern of the SARS cases in Asia

The severe acute respiratory syndrome (SARS) caused tremendous damage to many Asia countries, especially China. The transmission process and outbreak pattern of SARS is still not well understood. This study aims to find a simple model to describe the outbreak pattern of SARS cases by using SARS case data commonly released by governments. The outbreak pattern of cumulative SARS cases is expected to be a logistic type because the infection will be slowed down due to the increasing control effort by people and/or due to depletion of susceptible individuals. The increase rate of SARS cases is expected to decrease with the cumulative SARS cases, as described by the traditional logistical model, which is widely used in population dynamic studies. The instantaneous rate of increases were significantly and negatively correlated with the cumulative SARS cases in mainland of China (including Beijing, Hebei, Tianjin, Shanxi,the Autonomous Region of Inner Mongolia) and Singapore. The basic reproduction number R0 in Asia ranged from 2.0 to 5.6 (except for Taiwan, China). The R0 of Hebei and Tianjin were much higher than that of Singapore, Hongkong, Beijing, Shanxi, Inner Mongolia, indicating SARS virus might have originated differently or new mutations occurred during transmission. We demonstrated that the outbreaks of SARS in many regions of Asia were wall described by the logistic model, and the control measures implemented by governments are effective. The maximum instantaneous rate of increase, basic reproductive number, and maximum cumulative SARS cases were also calculated by using the logistic model.     

重组SARS冠状病毒S蛋白的原核表达研究

目的克隆表达SARS冠状病毒的主要结构蛋白(S蛋白)。方法合成SARS冠状病毒S蛋白特异性基因片断并克隆入pET32a原核表达载体,转化BL21菌,经IPTG诱导高效表达得到重组S蛋白,并通过W estern印迹对重组蛋白质进行鉴定。结果重组蛋白质经镍柱亲和层析得到了部分纯化,免疫动物后得到SARS病毒的多克隆抗体。结论经E lisa检测,表达的重组S蛋白基本具备检测病人血清中抗SARS病毒IgG和IgM的能力,可进一步用于S蛋白功能研究与SARS诊断试剂盒的研制。     

Genome sequence variation analysis of two SARS coronavirus isolates after passage in Vero cell culture

SARS coronavirus is an RNA virus whose replication is error-prone, which provides possibility for escape of host defenses, and even leads to evolution of new viral strains during the passage or the transmission. Lots of variations have been detected among different SARS-CoV strains. And a study on these variations is helpful for development of efficient vaccine. Moreover, the test of nucleic acid characterization and genetic stability of SARS-CoV is important in the research of inactivated vaccine. The whole genome sequences of two SARS coronavirus strains after passage in Vero cell culture were determined and were compared with those of early passages, respectively. Results showed that both SAPS coronavirus strains have high genetic stability, although nearly 10 generations were passed. Four nucleotide variations were observed between the second passage and the llth passage of Sinol strain for identification of SARS inactivated vaccine. Moreover, only one nucleotide was different between the third passage and the 10th passage of Sino3 strain for SARS inactivated vaccine. Therefore, this study suggested it was possible to develop inactivated vaccine against SARS-CoV in the future.     

SARS冠状病毒N蛋白的表达及二级结构预测分析

通过RT-PCR获得SARS冠状病毒N蛋白基因，分别克隆到原核表达载体pET21a，pET32a和pGEX-4T-1中，将3种重组质粒pET2la-N，pET32a-N和pGEX-4T-1-N分别转化大肠杆菌BL21(DE3)，经IPTG诱导，细菌中分别表达出约46kD的重组N蛋白、约60kD的6xHis-N融合蛋白和约70kD的GST-N融合蛋白，表达量分别达总蛋白的45％、40％和30％．进一步的分析表明：6xHis-N融合蛋白在大肠杆菌中为可溶性表达，该可溶性组分占细菌裂解液的70％左右，且能被6xHis抗体所识别．用蛋白分析软件对N蛋白进行了序列分析和二级结构预测．SARS冠状病毒N蛋白在大肠杆菌中的高效可溶性表达，有助于进一步结晶后进行X射线晶体衍射分析其结构与功能．     

用计算流体力学方法研究非典型肺炎病毒颗粒的分布

通过分析非典型肺炎（SARS）病毒颗粒在空气中随气流绕过建筑物后的运动过程和分布情况,研究了病毒颗粒在空气中的扩散、聚集和分布情况,得到了病毒颗粒在空气中的动态流型、相关的影响区范围以及主要扩散方向．提供了在受到病毒污染的建筑物后面设置有效隔离带的计算流体力学（CFD）研究数据,给出了一种建筑物群位置合理排列的CFD研究方法．     

高亲和力钠离子依赖二羧酸转运蛋白基因的克隆、表达及亚细胞定位研究

为了研究高亲和力钠离子依赖二羧酸转运蛋白(high affinity sodium-dependent dicarboxylate transporter,SDCT2,NaDC3)的功能,从小鼠肾组织中克隆出了其cDNA基因,并对其结构特征、基因表达谱及细胞内定位情况进行了分析。结果显示NaDC3蛋白由600个氨基酸组成,同源性分析表明其氨基酸序列与大鼠及人NaDC3分别有97％和87％相同。二级结构分析显示,该蛋白有13个跨膜α-螺旋区。Northern杂交显示该基因可在肾、肝、脑、胎盘等多种组织中表达。激光共聚焦显微镜观察显示该蛋白定位于肾小管上皮细胞膜上。     

一种基于最优局部信息融合的蛋白质-亚细胞定位预测方法

 基于蛋白质的合成及分选机制,提出了一种新的蛋白质亚细胞定位预测方法。先采用遍历搜索技术,找出各种亚细胞蛋白质序列分选信号和成熟蛋白质之间的最佳分割位点,把蛋白质序列分为两条子序列,计算这两条子序列中的氨基酸组份并将它们融合起来作为整条蛋白质序列的特征,然后构造用于识别每类蛋白质的最佳子分类器,再根据最大化原则组建集成分类器。在NNPSL数据集上,采用5重交叉验证方法对本文方法进行测试,原核和真核两个蛋白质序列子集分别取得94.1%和87.5%的总体预测精度。同时,此方法在一些蛋白质序列中找到的分割位点与真实生物现象相吻合,能为预测蛋白质序列的剪切位点提供参考信息。     

Bioinformatic Analysis of Putative Gene Products Encoded in SARS—HCoV Genome

The cause of severe acute respiratory syndrome (SARS) has been identified as a new coronavirus named as SARS-HCoV. Using bioinformatic methods, we have performed a detailed domain search. In addition to the viral structure proteins, we have found that several putative polypeptides share sequence similarity to known domains or proteins. This study may provide a basis for future studies on the infection and replication process of this notorious virus.     

引起人非典型性肺炎的冠状病毒基因组与其它冠状病毒基因组的初步比较

一种在世界范围内突然爆发的致命流行病——急性呼吸窘迫综合症(SARS)击倒了数干人，一种全新的冠状病毒被认为是其病原．5个SARS相关冠状病毒的全基因组序列已经完成．我们进行了SARS相关冠状病毒和其它冠状病毒的基因组进化分析和序列比较，结果显示：1．SARS相关冠状病毒不直接来自于任何已知的冠状病毒；2．E蛋白的基因可能是在近期从其它病毒横向转移到SARS病毒中来的；3．Sl和S2基因发生了较大范围的缺失或插入突变．这些基因横向转移和突变改变了SARS相关病毒的表面结构和抗原性，极有可能是导致其获得侵染人类细胞的主要原因．     

传染性非典型肺炎病毒核蛋白的表达与活性检测

用PCR方法，人工合成传染性非典型肺炎病毒(SARS-CoV)核蛋白(N)全编码基因，并构建原核表达载体．在大肠杆菌中进行表达．结果重组N蛋白表达产量占菌体总蛋白的40％以上，主要以可溶形式存在．用SARS患者急性期血清进行蛋白印迹检测，表明可溶形式和包含体形式均有明显活性．包含体形式的重组蛋白经纯化后纯度可达90％以上，活性与纯化前相当，可作为SARS抗体诊断试剂盒的抗原原料．     

SARS相关冠状病毒刺突糖蛋白的研究(综述)

概述了SARS—CoV的S蛋白的结构及功能相关研究。严重急性呼吸综合症相关的冠状病毒(SARS-CoV)引起2003年我国南方非典型肺炎爆发流行,波及多个国家和地区。目前全球许多学对SARS-CoV进行了广泛的研究,发现S蛋白是病毒表面的主要蛋白,它构成冠状病毒科特征性的冠状样结构,在严重急性呼吸综合症的发病机制起着关键性作用,可介导表达相关受体的宿主细胞感染。现已鉴定出SARS-CoV的S蛋白相关受体,同时它在抗病毒感染中是一个关键靶蛋白。     

Molecular phylogeny of coronaviruses including human SARS-CoV

The outbreak of SARS sets an urgent task to reveal the origin of human SARS-CoV, i.e. its relation to other known species of coronavirus, and to trace the genetic variation in the spreading process of SARS. Partial answer to the problem may be obtained from phylogenetic analy-sis of available genomes. We call a phylogenetic tree of different species of coronavirus including the human SARS-Cov a CoV Tree and that of different isolates of SARS-CoV a SARS Tree. CoV trees have been c…     

广州市SARS流行的数学建模与干预措施的定量评估

构建了反映SARS传播过程的动力学模型,利用模拟退火算法对2003年广州市的SARS疫情进行了研究,得到了重要流行病学参数——潜伏期、感染期、基本再生数与有效再生数的最优估计,结果表明:广州市SARS传播的平均潜伏期为4d,平均感染期为7.7d,基本再生数为3.8,疫情得到控制后的有效再生数为0.6,感染期的变化对广州市SARS疫情的变化趋势有重要影响.最后,采用情景模拟方法,定量评估了4类干预措施——疫苗接种率、应急反应时间、三早措施与综合防控对广州市SARS疫情的影响.     

Genome sequencing and characterization analysis of a Beijing isolate of chicken coronavirus infectious bronchitis virus

Avian infectious bronchitis virus (AIBV) is classified as a member of the genus coronavirus in the family coronaviridae. The enveloped virus has a positive-sense, single-stranded RNA genome of approximately 28 kilo-bases,which has a 5‘ cap structure and 3‘ polyadenylation tract.The complete genome sequence of infectious bronchitis virus (IBV), Beijing isolate, was determined by cloning sequencing and primer walking. The whole genome is 27733 nucleotides in length, has ten open reading frames:5′-orfla-orflab-s-3a-3b-e-m- 6a-6b-n-3′. Alignments of the genome sequence of IBV Beijing isolate with those of two AIBV strains and one SARS coronavirus were performed respectively. The genome sequence of IBV Beijing isolate compared with that of the IBV strain LX4 (uncompleted, 19440 bp in size) was 91.2% similarity. However, the full-length genome sequence of IBV Beijing isolate was 85.2% identity to that of IBV Strain Beaudette, and was only 50.8% homology to that of SARS coronavirus. The results showed that the genome of IBV has remarkable variation. And IBV Beijing isolate is not closely related to SARS coronavirus. Phylogenetic analyses based on the whole genome sequence, S protein, M protein and N protein, also showed that AIBV Bering isolate is lone virus in group Ⅲ and is distant from SARS coronavirus. In conclusion, this study will contribute to the studies of diagnosis and diseases control on IBV in China.     

玉米丝黑穗病菌的蛋白质多态性

对采自我国主要玉米产区的玉米丝黑穗病菌不同菌株在蛋白质和酶学水平上的多态性进行了试验研究,并进行了聚类分析.结果表明:玉米丝黑穗病菌在蛋白质和同工酶水平上存在着明显的分化现象.依据谱带聚类分析可以将23个菌株分为6组.同时发现,来自不同地区的菌株同工酶谱带无明显的变化规律,这可能表明病菌在同工酶和蛋白质水平上的生理分化地域性不明显.     

富集稳定同位素示踪研究钐、镱在大鼠肝脏中的亚细胞分布

采用可活化富集稳定同位素¹⁵²Sm和¹⁶⁸Yb作为示踪剂,结合差速离心分离和中子活化分析技术(NAA)初步研究了稀土元素Sm和Yb在大鼠肝脏亚细胞组分中的分布。分析结果表明,Sm和Yb在亚细胞组分中的浓度分布为：溶酶体>微粒体>线粒体>细胞核>胞液。线粒体中Sm和Yb所占比例最高,而细胞核中最低。     

麻疯树(Jatropha curcas)毒蛋白curcin基因家族成员的分离和描述

麻疯树curcin基因家族中4个成员通过PCR扩增被分离．它们都不合有内含子,序列分析表明它们编码Ⅰ型核糖体失活蛋白（Ribosome-Inactivating Proteins,RIPs）,证明curcin基因如同大多数RIPs一样由多基因家族编码．四个curcin基因家族成员和另两个已知curcin基因家族成员的开放阅读框（Open Reading Frame,ORF）的序列比对结果显示curcin基因家族成员至少可分为两个亚类群,亚类群之间的氨基酸序列相似性低于88％．分别将这4个curcin基因家族成员命名为curA2、curA3、curB2、curB3．对四条基因启动子区和ORF生物信息学分析推测CurB2、curB3可能是被真菌及逆境诱导的curcin基因家族成员全长,而curA2、curA3可能是麻疯树胚乳贮存的curcin基因家族成员全长．Southern杂交结果显示,麻疯树基因组中至少有3个以上curcin基因家族成员．