NMR studies on the surface accessibility of the archaeal protein Sso7d by using TEMPOL and Gd(III)(DTPA-BMA) as paramagnetic probes
NMR studies on the surface accessibility of the archaeal protein Sso7d by using TEMPOL and Gd(III)(DTPA-BMA) as paramagnetic probes
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DOI：
10.1016/j.bpc.2008.07.003
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发表时间：
2008-10-01
影响因子：
3.8
通讯作者：
Niccolai, Neri
中科院分区：
文献类型：
--
作者：
Bernini, Andrea;Venditti, Vincenzo;Niccolai, Neri
了解蛋白质是如何被周围的分子所接近的，对于增加我们在原子分辨率上对生命的认识是至关重要的。在这里，一个多功能的小蛋白，古菌蛋白Sso 7 d从硫磺硫化叶菌，表面可及性已被调查，通过使用TEMPOL和Gd（III）（DTPA-BMA）作为顺磁探针。Sso 7 d的DNA结合结构域似乎对TEMPOL和Gd（III）（DTPA-BMA）都非常接近。H-1-N-15 HSQC蛋白骨架酰胺相关性的顺磁衰减曲线的差异，在后者的顺磁探针的存在下观察到的，与TEMPOL的N-氧基部分的氢键受体能力表面暴露的Sso 7 d酰胺基团是一致的。通过使用钆配合物作为顺磁探针，实现了Sso 7 d结构特征和衰减曲线之间的更好的一致性。有趣的是，注意到蛋白质P环区域，尽管由可用的蛋白质结构预测的高表面暴露，但不被TEMPOL接近，并且仅部分地被Gd（III）（DTPA-BMA）接近。(C)2008 Elsevier B. V.保留所有权利。
Understanding how proteins are approached by surrounding molecules is fundamental to increase our knowledge of life at atomic resolution. Here, the surface accessibility of a multifunctional small protein, the archaeal protein Sso7d from Sulfolobus solfataricus, has been investigated by using TEMPOL and Gd(III)(DTPA-BMA) as paramagnetic probes. The DNA binding domain of Sso7d appears very accessible both to TEMPOL and Gd(III)(DTPA-BMA). Differences in paramagnetic attenuation profiles of H-1-N-15 HSQC protein backbone amide correlations, observed in the presence of the latter paramagnetic probes, are consistent with the hydrogen bond acceptor capability of the N-oxyl moiety of TEMPOL to surface exposed Sso7d amide groups. By using the gadolinium complex as a paramagnetic probe a better agreement between Sso7d structural features and attenuation profile is achieved. It is interesting to note that the protein P-loop region, in spite of the high surface exposure predicted by the available protein structures, is not approached by TEMPOL and only partially by Gd(III)(DTPA-BMA). (C) 2008 Elsevier B.V. All rights reserved.