Probing conformational stability and dynamics of erythroid and nonerythroid spectrin: effects of urea and guanidine hydrochloride.
Probing conformational stability and dynamics of erythroid and nonerythroid spectrin: effects of urea and guanidine hydrochloride.
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DOI：
10.1371/journal.pone.0116991
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Chakrabarti A
中科院分区：
文献类型：
--
作者：
Patra M;Mukhopadhyay C;Chakrabarti A
我们已经研究了两个同源的膜骨架蛋白，红细胞和非红细胞血影蛋白，在其二聚体和四聚体形式分别在尿素和盐酸胍（GuHCl）的存在下展开过程中的构象稳定性。利用荧光光谱和圆二色性（CD）光谱研究了结合态1-苯胺基萘-8-磺酸（ANS）的色氨酸固有荧光、各向异性、远紫外CD和外源荧光的变化。两种蛋白质的化学去折叠都是可逆的，可以描述为两种状态的转变。折叠的红细胞血影蛋白和非红细胞血影蛋白直接转化为未折叠的单体，而不形成任何中间体。荧光猝灭，各向异性，ANS结合和动态光散射数据表明，在低浓度的变性剂（高达1 M）的存在下，氢键网络和货车范德华相互作用发挥作用，诱导在四级和三级结构的变化，而没有完全解离的亚基。这是第一次报道两个大蠕虫样，多结构域的蛋白质遵守双重规则，这是常见的小球状蛋白。二聚体血影蛋白的稳定化自由能（ΔGu H2 0）比四聚体血影蛋白低20 kcal/mol。
We have studied the conformational stability of the two homologous membrane skeletal proteins, the erythroid and non-erythroid spectrins, in their dimeric and tetrameric forms respectively during unfolding in the presence of urea and guanidine hydrochloride (GuHCl). Fluorescence and circular dichroism (CD) spectroscopy have been used to study the changes of intrinsic tryptophan fluorescence, anisotropy, far UV-CD and extrinsic fluorescence of bound 1-anilinonapthalene-8-sulfonic acid (ANS). Chemical unfolding of both proteins were reversible and could be described as a two state transition. The folded erythroid spectrin and non-erythroid spectrin were directly converted to unfolded monomer without formation of any intermediate. Fluorescence quenching, anisotropy, ANS binding and dynamic light scattering data suggest that in presence of low concentrations of the denaturants (up-to 1M) hydrogen bonding network and van der Waals interaction play a role inducing changes in quaternary as well as tertiary structures without complete dissociation of the subunits. This is the first report of two large worm like, multi-domain proteins obeying twofold rule which is commonly found in small globular proteins. The free energy of stabilization (ΔGu H 2 0) for the dimeric spectrin has been 20 kcal/mol lesser than the tetrameric from.
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影响因子：
2.9
作者：
An, Xiuli;Zhang, Xihui;Mohandas, Narla
通讯作者：
Mohandas, Narla
影响因子：
6.8
作者：
Dobson, Christopher M.;Karplus, Martin
通讯作者：
Karplus, Martin
DOI：
10.1073/pnas.0604580103
发表时间：
2006-11-28
影响因子：
11.1
作者：
Batey, Sarah;Clarke, Jane
通讯作者：
Clarke, Jane
影响因子：
5.6
作者：
Ekman, D;Björklund, ÅK;Elofsson, A
通讯作者：
Elofsson, A
影响因子：
4.1
作者：
Del Vecchio, P;Graziano, G;Manco, G
通讯作者：
Manco, G