摘要
正常细胞的朊蛋白(PrPC)代谢和构象的改变是引发动物和人类可传播性海绵状脑病(transmissiblespongiformencephalopathies,TSEs)的根本原因。将羊瘙痒病(scrapie)仓鼠适应株263K颅内接种仓鼠,在接种后的第20、40、50、60、70、80天,通过Westernblot动态检测仓鼠脑中PrP存在的形式。结果在接种后第40天,在感染动物脑组织中即检测到PrPSc分子,比临床症状出现的时间早(平均潜伏期为66 7±1 1天),且无糖基化形式的PrP分子所占百分比在接种后期增加明显。除了标准分子量大小(30kD～35kD)的PrP分子外,在感染动物脑中存在着高分子量和低分子量形式的PrP分子。定量分析显示,随着接种潜伏期的延长,不同形式PrP分子的含量也在增加,其中低分子量形式的PrP分子与临床症状的出现密切相关。蛋白去糖基化实验表明,在感染动物脑组织中,除了标准分子量大小的PrP蛋白外,还存在一条更小分子量的PrP条带,而正常动物脑组织仅存在标准大小的PrP分子。低分子量形式的PrP分子具有与全长PrP分子相类似的糖基化模式。结果提示,scrapie263K感染的仓鼠脑组织中存在不同分子形式的PrPSc,其PrP分子的代谢可能不同于正常动物。
Metabolic and conformatio nal alterations of the cellular pr ion protein(PrP^C)are the essential causes of transmissible spongiform encephalopathies in human and anim als.A hamster-adapted scrapie agen t 263K was intracerebrally inocula ted into Syrian hamsters and the differen t forms of the abnormal prion pro tein(PrP^(Sc))were dynamically detect ed on the 20^(th),40^(th),50^(th),60^(th ),70^(th),and 80^(th) day post-inoculati on by Western blot.PrP^(Sc) was firstly det ected in the brain tissues of the animals 40 days post-inoculation,t hat was much earlier than the onse t of the disease (the mean incubat ion period is 66.7±1.1 days).Besid es the PrP with standard molecular weight (30-35kD),various high mole cular masses of PrP as well as the low were repeatedly identified fro m the infected brains.The amounts of these heterogeneous PrP increas ed along with the prolongation of incubation,while the appearance of the low molecular mass of PrP in b rain tissues was most probably dis ease-specific.Deglycosylation assa ys identified another PrP fragment with much lower molecular weight i n the infected brains in addition to the PrP with standard molecular weight,whereas only the latter cou ld be found in the healthy animals .The truncated PrP in the infected brains may have the similar glycos ylation patterns as the full-lengt h PrP.Moreover,the percentage of n on-glycosylated PrP increased dram atically at the terminus of the il lness.These results suggest that variou s molecular patterns of PrP^(Sc) may indwell in brain tissues during th e infection.The metabolism of PrP in the infected hamsters may diffe r from the healthy ones.
出处
《病毒学报》
CAS
CSCD
北大核心
2003年第4期324-329,共6页
Chinese Journal of Virology
基金
国家自然科学基金委项目(30070038)
国家自然科学基金委重点项目(30130070)
国家863计划项目(2001AA215391)资助
