Recombinant prion protein refolded with lipid and RNA has the biochemical hallmarks of a prion but lacks in vivo infectivity.
Recombinant prion protein refolded with lipid and RNA has the biochemical hallmarks of a prion but lacks in vivo infectivity.
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DOI：
10.1371/journal.pone.0071081
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Priola SA
中科院分区：
文献类型：
--
作者：
Timmes AG;Moore RA;Fischer ER;Priola SA
在朊病毒感染过程中，朊病毒蛋白（PrPC）的正常蛋白酶敏感构象通过种子聚合转化为蛋白酶抗性大大增加的异常感染性构象（PrPSc）。在体外，蛋白质错误折叠循环扩增（PMCA）使用朊病毒感染的脑匀浆中的PrPSc作为起始种子来转化PrPC并触发PrPSc在许多扩增循环中的自我繁殖。虽然PMCA反应产生高水平的蛋白酶抗性PrP，但感染滴度通常低于脑源性PrPSc。最近，在脂质和RNA存在但不存在任何起始PrPSc种子的情况下，使用细菌衍生的重组PrP（rPrP）的PMCA技术已用于产生感染性朊病毒，该朊病毒在野生型小鼠中以相对较短的孵育时间引起疾病。这些数据表明，脂质和/或RNA作为辅因子促进高水平朊病毒感染性的从头形成。使用通过两种不同技术纯化的rPrP，我们产生了一种自繁殖的抗蛋白酶的rPrP分子，无论使用的RNA和脂质的量如何，其分子量、抗蛋白酶性和不溶性与PrPSc相似。然而，我们无法检测朊病毒感染性在我们的任何反应，无论是细胞培养或动物生物测定。这些结果表明，自我繁殖成蛋白酶抗性不溶性构象的能力不是唯一的感染性PrP分子。他们认为RNA和脂质辅因子的存在可能有助于PrP自发重折叠成感染性形式，同时也允许从头形成自繁殖但非感染性的rPrP-res。
During prion infection, the normal, protease-sensitive conformation of prion protein (PrPC) is converted via seeded polymerization to an abnormal, infectious conformation with greatly increased protease-resistance (PrPSc). In vitro, protein misfolding cyclic amplification (PMCA) uses PrPSc in prion-infected brain homogenates as an initiating seed to convert PrPC and trigger the self-propagation of PrPSc over many cycles of amplification. While PMCA reactions produce high levels of protease-resistant PrP, the infectious titer is often lower than that of brain-derived PrPSc. More recently, PMCA techniques using bacterially derived recombinant PrP (rPrP) in the presence of lipid and RNA but in the absence of any starting PrPSc seed have been used to generate infectious prions that cause disease in wild-type mice with relatively short incubation times. These data suggest that lipid and/or RNA act as cofactors to facilitate the de novo formation of high levels of prion infectivity. Using rPrP purified by two different techniques, we generated a self-propagating protease-resistant rPrP molecule that, regardless of the amount of RNA and lipid used, had a molecular mass, protease resistance and insolubility similar to that of PrPSc. However, we were unable to detect prion infectivity in any of our reactions using either cell-culture or animal bioassays. These results demonstrate that the ability to self-propagate into a protease-resistant insoluble conformer is not unique to infectious PrP molecules. They suggest that the presence of RNA and lipid cofactors may facilitate the spontaneous refolding of PrP into an infectious form while also allowing the de novo formation of self-propagating, but non-infectious, rPrP-res.
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影响因子：
48
作者：
Atarashi, Ryuichiro;Moore, Roger A.;Caughey, Byron
通讯作者：
Caughey, Byron
DOI：
10.1073/pnas.0404650101
发表时间：
2004-08-17
影响因子：
11.1
作者：
Bieschke, J;Weber, P;Kretzschmar, H
通讯作者：
Kretzschmar, H
影响因子：
6.7
作者：
Chesebro B;Race B;Meade-White K;Lacasse R;Race R;Klingeborn M;Striebel J;Dorward D;McGovern G;Jeffrey M
通讯作者：
Jeffrey M
影响因子：
3.8
作者：
Hill, AF;Antoniou, M;Collinge, J
通讯作者：
Collinge, J
影响因子：
5.4
作者：
Baron, GS;Magalhaes, AC;Caughey, B
通讯作者：
Caughey, B