共查询到19条相似文献，搜索用时 171 毫秒
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3.1.3 PrP~(BSE)的形成 PrP~C转变为PrP~(BSE)(牛海绵状脑病朊病毒蛋白)机制尚不完全清楚,但普遍被接受的机制有二种,其主要依据一是PrP~C与PrP~(Sc)一级结构相同,而二级结构、三级结构不同;二是PrP~C不发生多分子聚集,而PrP~(Sc)可发生多分子聚集形成淀粉样纤维(痒病相关纤维,scrapie associated fabril,SAF);三是外源PrP~(Sc)能促进PrP~C向PrP~(Sc)的转变。 相似文献
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大肠杆菌F18ac菌毛FedA蛋白的表达与鉴定 总被引：5，自引：0，他引：5
根据已经发表的F18ac菌毛A亚单位的基因序列(FedA)设计一对引物,利用PCR技术从重组质粒T 8813A 中扩增到一段序列,并按预定的阅读框插入表达性质粒载体pGEX 6p 1中的谷胱苷肽转移酶(GST)基因的下游,获得重组质粒pPFedA/ac,并转化大肠杆菌BL 21 获得重组菌PPFedA/ac。琼脂糖凝胶电泳、序列测定及分析表明,该序列大小为456 bp,与已发表的FedA/ac结构编码序列完全一致。通过对菌体裂解物的SDS PAGE 分析以及Western blotting 鉴定,证明重组大肠杆菌PP FedA/ac的可以表达融合蛋白形式的FedA/ac (命名为GST FedA/ac),即FedA/ac蛋白(15.317 ku)与谷胱苷肽转移酶(27.335 ku)相连组成分子量为42.652 ku的融合蛋白。利用GST FedA/ac制备的兔抗GST FedA/ac 血清与大肠杆菌F107/86 株( F18ab )、2 134 P 株(F18ac )进行的玻板凝集试验呈现阳性反应,进一步表明了表达的正确性。 相似文献
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<正> 养蚕中流行的家蚕浓核病,是造成蚕茧歉收的原因之一。本病是由家蚕浓核病病毒(BmDNV)感染蚕体后引起发病的,这种病毒是一种没有包涵体的昆虫病毒,与过去报导的传染性软化病病毒(IFV)不同,浓核病病毒为直径21nm的球状粒子,病毒核酸为单链DNA,侵入家蚕中肠,在园筒细胞核内形成病毒粒子,而传染性软化病病毒为单链RNA,直径约27nm的球状粒子,侵染家蚕中肠杯状细胞,在细胞质内形成病毒粒子。 相似文献
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通过病毒提纯、电镜观察、病毒核酸性状鉴定、病毒蛋白测定、血清学反应、品种感染性及理化因素处理等方法对广东蚕区采集的家蚕浓核病病毒样品进行了分析。结果是:广东家蚕浓核病病毒为直径20nm左右的球状粒子;病毒核酸为单链DNA;顺德株病毒蛋白有6个亚基,南海株病毒蛋白有4个亚基;其它理化性状均与中国株DNV相似。因此认为,广东蚕区发生的浓核病病毒亦属细小病毒科(Parvoviridae)、浓核病毒属(Densovirus)。但顺德株病毒除有直径20nm的粒子外,还观察到有直径较小的球状粒子,病毒蛋白构成与中国株DNV有所不同,有待进一步研究。另外,广东各株浓核病病毒对高温、甲醛、漂白粉、石灰浆等的耐受力较强。 相似文献
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鸡传染性支气管炎的流行及防控 总被引：1，自引：0，他引：1
1 病原特性
鸡传染性支气管炎(Infectious bronchitis,IB)是由鸡传染性支气管炎病毒(Infectious bronchitis virus,IBV)引起的一种急性高度传染性疾病.IBV为有囊膜单股RNA病毒,病毒粒子呈多形性,大多数为球形,直径约60～160 nm,囊膜表面有棒状纤突.传染性支气管炎病毒粒子含有3种主要结构蛋白:纤突糖蛋白(S)、膜蛋白(M)、内部核衣壳蛋白(N).S蛋白位于病毒粒子的表面,由S1和S2两种糖蛋白组成. 相似文献
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水貂阿留申病毒结构蛋白与非结构蛋白的研究进展 总被引：1，自引：1，他引：0
水貂阿留申病毒(Aleutian mink disease virus,ADV)是一种主要侵染水貂的自主复制型细小病毒,是一种在水貂中广泛存在的重要病原体。病毒粒子的蛋白分为结构蛋白(VP1、VP2)和非结构蛋白(NS1、NS2)两类。VP1蛋白对病毒粒子产生感染性有重要作用;VP2蛋白是主要免疫功能区,能刺激机体产生中和抗体;NS1和NS2主要参与病毒的复制和基因的表达调节。文中对近年来国内外学者关于水貂阿留申病毒结构蛋白和非结构蛋白的研究情况进行归纳和总结。 相似文献
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中蜂囊状幼虫病病毒的研究 总被引：1，自引：0，他引：1
中蜂囊状幼虫病是一种严重危害中蜂生产的病毒病,1972年首先在广东省发生,迅速蔓延全国。经电镜观察,该病是一种直径为28～30nm 病毒粒子引起的,暂定名为 CS-BV(Chinese Sacbrood Virus)。意蜂囊状幼虫病发病历史较久,早在1917年 White(美国)曾对该病的症状进行描述,随后各国学者对意蜂囊状幼虫病病毒 SBV(Sacb一rood Virus)进行深入的研究,对病毒的形态、浮力密度、沉降系数、核糖核酸和核蛋白质的分子量等进行了测定。1982年 相似文献
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Recent developments in prion disease research: diagnostic tools and in vitro cell culture models 总被引：2，自引：0，他引：2
Sakudo A Nakamura I Ikuta K Onodera T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(4):329-337
After prion infection, an abnormal isoform of prion protein (PrP(Sc)) converts the cellular isoform of prion protein (PrP(C)) into PrP(Sc). PrP(C)-to-PrP(Sc) conversion leads to PrP(Sc) accumulation and PrP(C) deficiency, contributing etiologically to induction of prion diseases. Presently, most of the diagnostic methods for prion diseases are dependent on PrP(Sc) detection. Highly sensitive/accurate specific detection of PrP(Sc) in many different samples is a prerequisite for attempts to develop reliable detection methods. Towards this goal, several methods have recently been developed to facilitate sensitive and precise detection of PrP(Sc), namely, protein misfolding cyclic amplification, conformation-dependent immunoassay, dissociation-enhanced lanthanide fluorescent immunoassay, capillary gel electrophoresis, fluorescence correlation spectroscopy, flow microbead immunoassay, etc. Additionally, functionally relevant prion-susceptible cell culture models that recognize the complexity of the mechanisms of prion infection have also been pursued, not only in relation to diagnosis, but also in relation to prion biology. Prion protein (PrP) gene-deficient neuronal cell lines that can clearly elucidate PrP(C) functions would contribute to understanding of the prion infection mechanism. In this review, we describe the trend in recent development of diagnostic methods and cell culture models for prion diseases and their potential applications in prion biology. 相似文献
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Goldmann W 《Veterinary research》2008,39(4):30
Scrapie, bovine spongiform encephalopathy (BSE), and chronic wasting disease (CWD) are prion diseases in ruminants with considerable impact on animal health and welfare. They can also pose a risk to human health and control is therefore an important issue. Prion protein (PrP) genetics may be used to control and eventually eradicate animal prion diseases. The PrP gene in sheep and other representatives of the order Artiodactyles has many polymorphisms of which several are crucial determinants of susceptibility to prion diseases, also known as transmissible spongiform encephalopathies (TSE). This review will present the current understanding of PrP genetics in ruminants highlighting similarity and difference between the species in the context of TSE. 相似文献
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Vella LJ Greenwood DL Cappai R Scheerlinck JP Hill AF 《Veterinary immunology and immunopathology》2008,124(3-4):385-393
Prion diseases are transmissible neurodegenerative disorders affecting humans and a wide variety of animal species including sheep and cattle. The transmissible agent, the prion, is an abnormally folded form (PrP(Sc)) of the host encoded cellular prion protein (PrP(C)). Distribution of the prion protein in the fluids of species susceptible to these diseases is of importance to human health and the iatrogenic spread of prion disease. Aside from blood which is confirmed to be a source of prion infectivity, it is currently unclear which other body fluids harbor a significant transmission risk. In the current study we examined two ovine fluids; pseudo-afferent lymph and cerebral spinal fluid (CSF), for the presence of exosomes and concurrent enrichment of the normal, cellular form of the prion protein (PrP(C)). Here we demonstrate the existence of exosomes in both pseudo-afferent lymph and CSF isolated from sheep. In the CSF derived exosomes we were able to show an enrichment of PrP(C) over unfractionated CSF. This experimental approach suggests that CSF derived exosomes could be used as a novel means of detecting abnormal forms of the prion protein and provide an in vivo link between these vesicles and prion disease pathogenesis. 相似文献
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Transmissible spongiform encephalopathies (TSEs) or prion diseases are unique disorders that are not caused by infectious micro-organisms (bacteria or fungi), viruses or parasites, but rather seem to be the result of an infectious protein. TSEs are comprised of fatal neurodegenerative disorders affecting both human and animals. Prion diseases cause sponge-like degeneration of neuronal tissue and include (among others) Creutzfeldt-Jacob disease in humans, bovine spongiform encephalopathy (BSE) in cattle and scrapie in sheep. TSEs are characterized by the formation and accumulation of transmissible (infectious) disease-associated protease-resistant prion protein (PrP(Sc)), mainly in tissues of the central nervous system. The exact molecular processes behind the conversion of PrP(C) into PrP(Sc) are not clearly understood. Correlations between prion protein polymorphisms and disease have been found, however in what way these polymorphisms influence the conversion processes remains an enigma; is stabilization or destabilization of the prion protein the basis for a higher conversion propensity? Apart from the disease-associated polymorphisms of the prion protein, the molecular processes underlying conversion are not understood. There are some notions as to which regions of the prion protein are involved in refolding of PrP(C) into PrP(Sc) and where the most drastic structural changes take place. Direct interactions between PrP(C) molecules and/or PrP(Sc) are likely at the basis of conversion, however which specific amino acid domains are involved and to what extent these domains contribute to conversion resistance/sensitivity of the prion protein or the species barrier is still unknown. 相似文献
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Sylvie L Benestad Lars Austb? Michael A Tranulis Arild Espenes Ingrid Olsaker 《Veterinary research》2012,43(1):87
Prion diseases such as scrapie in small ruminants, bovine spongiform encephalopathy (BSE) in cattle and Creutzfeldt-Jakob disease (CJD) in man, are fatal neurodegenerative disorders. These diseases result from the accumulation of misfolded conformers of the host-encoded prion protein (PrP) in the central nervous system. To date naturally-occurring PrP free animals have not been reported. Here we describe healthy non-transgenic animals, Norwegian Dairy Goats, lacking prion protein due to a nonsense mutation early in the gene. These animals are predicted to be resistant to prion disease and will be valuable for research and for production of prion-free products. 相似文献
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Leach SP Salman MD Hamar D 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2006,7(1-2):97-105
Transmissible spongiform encephalopathies (TSEs) are a family of neurodegenerative diseases characterized by their long incubation periods, progressive neurological changes, and spongiform appearance in the brain. There is much evidence to show that TSEs are caused by an isoform of the normal cellular surface prion protein PrPC. The normal function of PrPC is still unknown, but it exhibits properties of a cupro-protein, capable of binding up to six copper ions. There are two differing views on copper's role in prion diseases. While one view looks at the PrPC copper-binding as the trigger for conversion to PrPSc, the opposing viewpoint sees a lack of PrPC copper-binding resulting in the conformational change into the disease causing isoform. Manganese and zinc have been shown to interact with PrPC as well and have been found in abnormal levels in prion diseases. This review addresses the interaction between select trace elements and the PrPC. 相似文献
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朊病毒研究进展 总被引：2，自引：0，他引：2
朊病毒是一种不含核酸的蛋白浸染子,主要引起人和动物的中枢神经疾病。目前,由其引起的朊病毒病在世界多国已有发生,危害严重,经济损失巨大,并对人类的健康构成很大威胁。该病毒蛋白是一种膜糖蛋白,至少有两种基本形式,即PrPc与PrPsc,PrPsc对紫外线及消毒剂有很强的抵抗力;朊蛋白基因是单拷贝基因,高度保守,但在物种间可能存在易感性相关基因。病毒的复制呈指数增长过程,需朊病毒结合因子参与。病毒的致病性在于正常的朊病毒蛋白PrPc转变为PrPsc,PrPsc是发病的直接原因。另外,对其检测和防治目前也有了新的方法及措施。文章就朊病毒概念、蛋白、基因、复制、致病机理及检测与防治作了综述。 相似文献
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Transmissible spongiform encephalopathies (TSEs) or prion diseases are unique disorders that are not caused by infectious micro-organisms (bacteria or fungi), viruses or parasites, but rather seem to be the result of an infectious protein. TSEs are comprised of fatal neurodegenerative disorders affecting both human and animals. Prion diseases cause sponge-like degeneration of neuronal tissue and include (among others) Creutzfeldt–Jacob disease in humans, bovine spongiform encephalopathy (BSE) in cattle and scrapie in sheep. TSEs are characterized by the formation and accumulation of transmissible (infectious) disease-associated protease-resistant prion protein (PrPSc), mainly in tissues of the central nervous system. The exact molecular processes behind the conversion of PrPC into PrPSc are not clearly understood. Correlations between prion protein polymorphisms and disease have been found, however in what way these polymorphisms influence the conversion processes remains an enigma; is stabilization or destabilization of the prion protein the basis for a higher conversion propensity? Apart from the disease-associated polymorphisms of the prion protein, the molecular processes underlying conversion are not understood. There are some notions as to which regions of the prion protein are involved in refolding of PrPC into PrPSc and where the most drastic structural changes take place. Direct interactions between PrPC molecules and/or PrPSc are likely at the basis of conversion, however which specific amino acid domains are involved and to what extent these domains contribute to conversion resistance/sensitivity of the prion protein or the species barrier is still unknown. 相似文献