Elongated oligomers in beta2-microglobulin amyloid assembly revealed by ion mobility spectrometry-mass spectrometry.
Elongated oligomers in beta2-microglobulin amyloid assembly revealed by ion mobility spectrometry-mass spectrometry.
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通过离子迁移谱-质谱法揭示 β2-微球蛋白淀粉样蛋白组装中的延长寡聚体。
DOI：
10.1073/pnas.0913046107
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发表时间：
2010
影响因子：
11.1
通讯作者：
Smith DP
中科院分区：
文献类型：
--
作者：
Smith DP
理解淀粉样蛋白疾病的关键是在原纤维组装的早期阶段形成的寡聚物种类的特征。本文采用电喷雾离子迁移谱质谱法对β2-微球蛋白（β 2 m）在淀粉样蛋白组装过程中形成的低聚物进行了鉴定和结构表征，结果表明β 2 m低聚物具有与原纤维形成前伸长组装体中排列的单体单元一致的碰撞截面。直接观察，分离和定量的瞬时低聚物物种揭示，单体到四聚体的人口通过滞后期，没有证据表明，在所采用的条件下，较大的低聚物物种的显着人口。通过观察14 N-和15 N-标记的寡聚体的亚基交换，在与淀粉样蛋白形成相当的浓度下，直接在系综内监测每个寡聚体种类的动态。数据分析显示，随着低聚物大小的增加，低聚物动力学降低，动态二聚体和三聚体物种与更稳定的三聚体和四聚体物种共存。所呈现的结果绘制了在原纤维形成的滞后期期间发生的事件，并清楚地了解了β 2 m寡聚体的结构特征和动态性质，证明了在原纤维形成期间存在由完整的淀粉样蛋白产生的伸长组装体。
The key to understanding amyloid disease is the characterization of oligomeric species formed during the early stages of fibril assembly. Here we have used electrospray ionisation-ion mobility spectrometry-mass spectrometry to identify and structurally characterize the oligomers formed during amyloid assembly fromβ2-microglobulin (β2m).β2m oligomers are shown to have collision cross-sections consistent with monomeric units arranged in elongated assemblies prior to fibril formation. Direct observation, separation, and quantification of transient oligomeric species reveals that monomers to tetramers are populated through the lag phase with no evidence for the significant population of larger oligomeric species under the conditions employed. The dynamics of each oligomeric species were monitored directly within the ensemble at concentrations commensurate with amyloid formation by observing the subunit exchange of14N- and15N- labeled oligomers. Analysis of the data revealed a decrease in oligomer dynamics concomitant with increasing oligomer size and the copopulation of dynamic dimeric and trimeric species with more stable trimeric and tetrameric species. The results presented map the events occurring during the lag phase of fibril formation and give a clear insight into the structural characteristics and dynamic nature of theβ2m oligomers, demonstrating the existence of elongated assemblies arising from an intact amyloidogenic protein during fibril formation.