Thermodynamic modulation of light chain amyloid fibril formation
Thermodynamic modulation of light chain amyloid fibril formation
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DOI：
10.1074/jbc.275.3.1570
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发表时间：
2000-01-21
影响因子：
4.8
通讯作者：
Carpenter, JF
中科院分区：
文献类型：
--
作者：
Kim, YS;Wall, JS;Carpenter, JF
为了进一步了解淀粉样变性的发病机制并开发抑制纤维形成的治疗策略，我们研究了：1)内在物理性质(热力学稳定性和氢-氚(H-D)交换率)与人免疫球蛋白轻链在体外形成淀粉样纤维的倾向之间的关系；以及2)外部调节这些性质对纤维形成的影响。淀粉样蛋白相关蛋白在体外很容易形成淀粉样纤维，并且比同源的非病理性蛋白具有更低的展开自由能，后者在体外不形成纤维。病理蛋白质的H-D交换要快得多，这表明它具有更大比例的部分折叠分子。热力学稳定剂蔗糖完全抑制病理性蛋白质的纤维形成，并将其物理参数的值移动到仅在缓冲液中测量的非病理性蛋白质的值。相反，尿素充分破坏了非病理性蛋白质的稳定性，使其测量的物理性质与缓冲液中的病理性蛋白质相同，并形成了纤维。因此，由轻链形成的纤维主要受热力学稳定性的控制；抑制淀粉样变性的合理策略是设计高亲和力配体，专门增加天然蛋白质的稳定性。
To obtain further insight into the pathogenesis of amyloidosis and develop therapeutic strategies to inhibit fibril formation we investigated: 1) the relationship between intrinsic physical properties (thermodynamic stability and hydrogen-deuterium (H-D) exchange rates) and the propensity of human immunoglobulin light chains to form amyloid fibrils in vitro; and 2) the effects of extrinsically modulating these properties on fibril formation. An amyloid-associated protein readily formed amyloid fibrils in vitro and had a lower free energy of unfolding than a homologous nonpathological protein, which did not form fibrils in vitro. H-D exchange was much faster for the pathological protein, suggesting it had a greater fraction of partially folded molecules. The thermodynamic stabilizer sucrose completely inhibited fibril formation by the pathological protein and shifted the values for its physical parameters to those measured for the nonpathological protein in buffer alone. Conversely, urea sufficiently destabilized the nonpathological protein such that its measured physical properties were equivalent to those of the pathological protein in buffer, and it formed fibrils. Thus, fibril formation by light chains is predominantly controlled by thermodynamic stability; and a rational strategy to inhibit amyloidosis is to design high affinity ligands that specifically increase the stability of the native protein.