Trimethylamine N-oxide-induced cooperative folding of an intrinsically unfolded transcription-activating fragment of human glucocorticoid receptor
Trimethylamine N-oxide-induced cooperative folding of an intrinsically unfolded transcription-activating fragment of human glucocorticoid receptor
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DOI：
10.1074/jbc.274.16.10693
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发表时间：
1999-04-16
影响因子：
4.8
通讯作者：
Thompson, EB
中科院分区：
文献类型：
--
作者：
Baskakov, IV;Kumar, R;Thompson, EB
最近鉴定的许多生物学上重要的蛋白质或蛋白质结构域是完全或部分非结构化的（未折叠的），允许研究这些蛋白质自然折叠的倾向的方法是有价值的。传统的生物物理方法使用酒精来驱动α-螺旋的形成提出了严重的问题，酒精诱导的结构的相关性，生物学上重要的构象。最近，我们说明了非凡的能力，天然存在的溶质，三甲胺N-氧化物（TMAO），迫使两个未折叠的蛋白质折叠到天然样的物种具有显着的功能活性。在目前的工作中，我们将这种技术应用于由残基1-500和残基77-262组成的重组人糖皮质激素受体片段。CD和荧光光谱表明，两者在水溶液中基本上是无序的。TMAO诱导的1-500片段的构象转变与三氟乙醇（TFE）不同，TMAO诱导的1-500片段的构象转变是协同的，具有独特结构的蛋白质的特征。
A number of biologically important proteins or protein domains identified recently are fully or partially unstructured (unfolded), Methods that allow studies of the propensity of such proteins to fold naturally are valuable. The traditional biophysical approaches using alcohols to drive alpha-helix formation raise serious questions of the relevance of alcohol-induced structure to the biologically important conformations. Recently we illustrated the extraordinary capability of the naturally occurring solute, trimethylamine N-oxide (TMAO), to force two unfolded proteins to fold to native-like species with significant functional activity. In the present work we apply this technique to recombinant human glucocorticoid receptor fragments consisting of residues 1-500 and residues 77-262. CD and fluorescence spectroscopy showed that both were largely disordered in aqueous solution. TMAO induced a condensed structure in the large fragment, indicated by the substantial enhancement in intrinsic fluorescence and blue shift of fluorescent maxima, CD spectroscopy demonstrated that the TMAO-induced structure is different from the alpha-helix-rich conformation driven by trifluoroethanol (TFE), In contrast to TFE, the conformational transition of the 1-500 fragment induced by TMAO is cooperative, a condition characteristic of proteins with unique structures.