Hot spots in prion protein for pathogenic conversion
Hot spots in prion protein for pathogenic conversion
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DOI：
10.1073/pnas.0702671104
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发表时间：
2007-07-17
影响因子：
11.1
通讯作者：
Katamine, Shigeru
中科院分区：
文献类型：
--
作者：
Kuwata, Kazuo;Nishida, Noriyuki;Katamine, Shigeru
朊病毒蛋白是传染性海绵状脑病（TSE）的关键分子，但从细胞形式（PrPc）转化为羊瘙痒症形式（PrPs（c））的确切机制仍然未知。在这里，我们发现了一个化学伴侣，以稳定的PrPc构象，并确定了热点，以阻止致病性转换。我们进行了计算机筛选，以找到适合于由经历天然和稀疏填充的高能态（PrP*）之间的构象重排的残基产生的“口袋”中的化合物，并直接与这些残基结合。在TSE感染的细胞培养模型中测试了44种选择的化合物，其中一种，2-吡咯烷-1-基-N-[4-[4-（2-吡咯烷-1-基-乙酰氨基）-苄基]-苯基]-乙酰胺，称为GN 8，有效地还原PrPsc。随后，发现给予GN 8延长了TSE感染小鼠的存活时间。异谱NMR和计算机模拟表明，特异性结合位点是A-S2环（N159）和螺旋B（V189、T192和K194）到B-C环（E196）的区域，表明这些远距离区域（热点）的插入阻碍了致病性转化过程。基于动力学的药物发现策略，在这里展示了集中在PrPc的热点，将开辟新的抗朊病毒药物的开发的道路。
Prion proteins are key molecules in transmissible spongiform encephalopathies (TSEs), but the precise mechanism of the conversion from the cellular form (PrPc) to the scrapie form (PrPs(c)) is still unknown. Here we discovered a chemical chaperone to stabilize the PrPc conformation and identified the hot spots to stop the pathogenic conversion. We conducted in silico screening to find compounds that fitted into a "pocket" created by residues undergoing the conformational rearrangements between the native and the sparsely populated high-energy states (PrP*) and that directly bind to those residues. Forty-four selected compounds were tested in a TSE-infected cell culture model, among which one, 2-pyrrolidin-lyi-N-[4-[4-(2-pyrrolidin-1-yl-acetylamino)-benzyl]-phenyl]-acetamide, termed GN8, efficiently reduced PrPsc. Subsequently, administration of GN8 was found to prolong the survival of TSE-infected mice. Heteronuclear NMR and computer simulation showed that the specific binding sites are the A-S2 loop (N159) and the region from helix B(V189,T192, and K194) to B-C loop (E196), indicating that the intercalation of these distant regions (hot spots) hampers the pathogenic conversion process. Dynamics-based drug discovery strategy, demonstrated here focusing on the hot spots of PrPc, will open the way to the development of novel anti-prion drugs.