Slow conformational dynamics in the hamster prion protein
Slow conformational dynamics in the hamster prion protein
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DOI：
10.1021/bi036123o
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发表时间：
2004-04-20
期刊：
影响因子：
2.9
通讯作者：
James, TL
中科院分区：
文献类型：
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作者：
Kuwata, K;Kamatari, YO;James, TL
虽然从细胞（PrPC）到羊瘙痒症（PrPSc）形式的动物朊病毒蛋白的构象转换的机制还有待阐明，证据正在积累，可能提供洞察原子分辨率的转换过程。在这里，我们显示的重组仓鼠朊病毒蛋白，rPrP（90-231）的缓慢波动动力学的关键方面，基于核磁共振弛豫分析，使用Carr-Purcell-Meiboom-Gill（CPMG）实验，并将它们与高压核磁共振结果进行详细比较。在微秒至毫秒的时间尺度上表现出缓慢波动的残基主要位于螺旋B和C（172-193和200-227）上，其包括先前通过高压NMR鉴定的中间构象体PrP* 中的局部无序区域[Kuwata，K.，例如，（2002）Biochemistry 41，12277-12283]。此外，两个假定的交换构象之间的化学位移差异得到的CPMG松弛分析和压力引起的化学位移变化的线性分量是合理相关的在个别残留物的网站。这些观察结果表明，CMPG松弛和压力变化反映缓慢的构象波动，这些缓慢的运动在PrPC相关的轨迹导致过渡到PrP*。
Although the mechanism of the conformational conversion from the cellular (PrPC) to the scrapie (PrPSc) form of animal prion proteins has yet to be elucidated, evidence is accumulating that may provide insight into the conversion process at atomic resolution. Here we show critical aspects of the slow fluctuation dynamics of the recombinant hamster prion protein, rPrP(90-231), based on NMR relaxation analysis using Carr-Purcell-Meiboom-Gill (CPMG) experiments, and compare them in detail with results from high-pressure NMR. Residues exhibiting slow fluctuations on the time scale of microseconds to milliseconds are mainly localized on helices B and C (172-193 and 200-227), which include locally disordered regions in an intermediate conformer, PrP*, identified previously by high-pressure NMR [Kuwata, K., et al., (2002) Biochemistry 41, 12277-12283]. Moreover, chemical shift differences between two putative exchanging conformers obtained by the CPMG relaxation analysis and the linear component of the pressure-induced chemical shift changes are reasonably correlated at individual residue sites. These observations suggest that both the CMPG relaxation and the pressure shifts reflect slow conformational fluctuations and that these slow motions in PrPC are related to the trajectories leading to the transition to PrP*.