Surprising Rigidity of Functionally Important Water Molecules Buried in the Lipid Headgroup Region.
Surprising Rigidity of Functionally Important Water Molecules Buried in the Lipid Headgroup Region.
复制标题
埋在脂质头基区域的功能重要水分子的惊人刚性。
DOI：
10.1021/jacs.2c02145
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发表时间：
2022-05-04
影响因子：
15
通讯作者：
Fu, Riqiang
中科院分区：
文献类型：
--
作者：
Zhang, Rongfu;Cross, Timothy A.;Peng, Xinhua;Fu, Riqiang
了解水动力学和结构是生物系统中的一个重要课题。在文献中通常认为，水合磷脂的界面水是高度移动的，在纳米至飞秒时间尺度范围内与本体水快速交换。虽然核磁共振（NMR）是结构和动力学研究的有力工具，但由于本体水和界面水之间的极端群体差异，直接探测水合磷脂中的界面水是非常具有挑战性的。我们开发了一种新的17 O固态NMR技术结合超高场磁体（35.2 T）直接探测功能重要的界面水。通过选择性地抑制占主导地位的散装水信号，我们观察到两个不同的水物种的头基区域的水合二肉豆蔻酰磷脂酰胆碱（DMPC）脂质双层的第一次。一种被称为“承压水”的水物种在化学上和动力学上不同于本体水（约0.17ppm的低场和稍短的自旋-晶格弛豫时间）。另一种被称为“束缚水”的水物种具有严重限制的运动和明显的化学位移（约12 ppm的高场）。此外，本体水不像纯水那样“自由”，这是由于与水分子的快速交换，水分子与脂质胆碱基团的相互作用微弱且短暂。这些新发现清楚地表明界面水分子的存在，这些水分子在核磁共振时间尺度（毫秒量级）上相对稳定，为表征生物大分子中毫秒或更慢时间尺度上的水动力学提供了机会。
Understanding water dynamics and structure is an important topic in biological systems. It is generally held in the literature that the interfacial water of hydrated phospholipids is highly mobile, in fast exchange with the bulk water ranging from the nano- to femtosecond timescale. Although nuclear magnetic resonance (NMR) is a powerful tool for structural and dynamic studies, direct probing of interfacial water in hydrated phospholipids is formidably challenging due to the extreme population difference between bulk and interfacial water. We developed a novel 17O solid-state NMR technique in combination with an ultra-high-field magnet (35.2 T) to directly probe the functionally important interfacial water. By selectively suppressing the dominant bulk water signal, we observed two distinct water species in the headgroup region of hydrated dimyristoylphosphatidylcholine (DMPC) lipid bilayers for the first time. One water species denoted as “confined water” is chemically and dynamically different from the bulk water (~0.17 ppm downfield and a slightly shorter spin-lattice relaxation time). Another water species denoted as “bound water” has severely restricted motion and a distinct chemical shift (~12 ppm upfield). Additionally, the bulk water is not as “free” as pure water, resulting from the fast exchange with the water molecules that weakly and transiently interact with the lipid choline groups. These new discoveries clearly indicate the existence of the interfacial water molecules that are relatively stable over the NMR timescale (on the order of milliseconds), providing an opportunity to characterize water dynamics on the millisecond or slower timescale in biomacromolecules.
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生物分子的水合壳中的水动力学。
影响因子：
62.1
作者：
Laage D;Elsaesser T;Hynes JT
通讯作者：
Hynes JT
DOI：
10.1073/pnas.2001083117
发表时间：
2020-06-02
影响因子：
11.1
作者：
Paulino, Joana;Yi, Myunggi;Cross, Timothy A.
通讯作者：
Cross, Timothy A.
影响因子：
3.5
作者：
Faure, C;Bonakdar, L;Dufourc, EJ
通讯作者：
Dufourc, EJ
影响因子：
2.2
作者：
KENTGENS, APM;LEMMENS, JJM;VEEMAN, WS
通讯作者：
VEEMAN, WS
影响因子：
4.4
作者：
Persson, Filip;Soderhjelm, Par;Halle, Bertil
通讯作者：
Halle, Bertil