Pf1 bacteriophage hydration by magic angle spinning solid-state NMR
Pf1 bacteriophage hydration by magic angle spinning solid-state NMR
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DOI：
10.1063/1.4903230
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发表时间：
2014-12-14
影响因子：
4.4
通讯作者：
McDermott, Ann E.
中科院分区：
文献类型：
--
作者：
Sergeyev, Ivan V.;Bahri, Salima;McDermott, Ann E.
高分辨率二维和三维异质结相关光谱（H-1-C-13，H-1-N-15和H-1-C-13-C-13 HETCOR）提供了Pf 1病毒粒子内部和外部水合水的详细表征。这种细长的病毒体（2000 nm x 7 nm）在小蛋白亚基的衣壳内含有高度拉伸的DNA，每个亚基只有46个氨基酸残基。HETCOR交叉峰已明确归属于25个氨基酸，包括大多数外部残基1-21以及病毒粒子内部深处的残基39-40和43-46。此外，靠近病毒体轴的DNA的脱氧核糖环与水接触。DNA和所有25个氨基酸残基的交叉峰组来自相同的水合水H-1共振;一些指定的残基不具有可交换的侧链质子。映射到结构模型的接触表明存在水“隧道”通过一个高度疏水性的区域的衣壳。本研究结果显着扩展和修改的结果，从较低的分辨率研究，并产生一个全面的水化表面地图的Pf 1。此外，通过顺磁弛豫增强可以区分内部水和外部水化水。内部水人口可以作为一个方便的本地化磁化水库的结构研究。(C)2014 AIP Publishing LLC.
High resolution two-and three-dimensional heteronuclear correlation spectroscopy (H-1-C-13, H-1-N-15, and H-1-C-13-C-13 HETCOR) has provided a detailed characterization of the internal and external hydration water of the Pf1 virion. This long and slender virion (2000 nm x 7 nm) contains highly stretched DNA within a capsid of small protein subunits, each only 46 amino acid residues. HETCOR cross-peaks have been unambiguously assigned to 25 amino acids, including most external residues 1-21 as well as residues 39-40 and 43-46 deep inside the virion. In addition, the deoxyribose rings of the DNA near the virion axis are in contact with water. The sets of cross-peaks to the DNA and to all 25 amino acid residues were from the same hydration water H-1 resonance; some of the assigned residues do not have exchangeable side-chain protons. A mapping of the contacts onto structural models indicates the presence of water "tunnels" through a highly hydrophobic region of the capsid. The present results significantly extend and modify results from a lower resolution study, and yield a comprehensive hydration surface map of Pf1. In addition, the internal water could be distinguished from external hydration water by means of paramagnetic relaxation enhancement. The internal water population may serve as a conveniently localized magnetization reservoir for structural studies. (C) 2014 AIP Publishing LLC.