Water behavior in bacterial spores by deuterium NMR spectroscopy.
Water behavior in bacterial spores by deuterium NMR spectroscopy.
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DOI：
10.1021/jp5025119
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发表时间：
2014-07-31
期刊：
影响因子：
--
通讯作者：
Rice CV
中科院分区：
文献类型：
--
作者：
Friedline AW;Zachariah MM;Johnson K;Thomas KJ 3rd;Middaugh AN;Garimella R;Powell DR;Vaishampayan PA;Rice CV
休眠的细菌孢子能够在没有营养的情况下长时间存活，承受恶劣的环境条件，并在条件有利时发芽成代谢活跃的细菌。许多因素都会影响这种硬度，包括孢子结构和保护 DNA 免受损伤的化合物的存在。众所周知，孢子核心的水含量在抵抗降解方面发挥着作用，但核心内水的确切状态仍然是一个讨论的话题。存在两种主要理论：要么孢子核心中的水大部分是不可移动的，并且核心及其成分处于玻璃态，要么核心是凝胶，其周围成分具有流动性水，而成分本身具有有限的流动性。使用氘固态核磁共振实验，我们检查了孢子核心中水的性质。我们的数据显示存在未结合水、结合水和含有不稳定氘核的氘化生物分子。氘-氢交换实验表明，大多数氘核无法被外部水接触。我们相信这些无法到达的氘核处于阻止交换的化学键合状态。变温核磁共振结果表明，孢子核心比凝胶状状态的预期更坚硬。然而，我们的刚性核心解释可能仅适用于干燥孢子，而凝胶核心可能存在于水悬浮液中。尽管如此，如果存在凝胶核心，则外部水无法接触到该凝胶核心。
Dormant bacterial spores are able to survive long periods of time without nutrients, withstand harsh environmental conditions, and germinate into metabolically active bacteria when conditions are favorable. Numerous factors influence this hardiness, including the spore structure and the presence of compounds to protect DNA from damage. It is known that the water content of the spore core plays a role in resistance to degradation, but the exact state of water inside the core is a subject of discussion. Two main theories present themselves: either the water in the spore core is mostly immobile and the core and its components are in a glassy state, or the core is a gel with mobile water around components which themselves have limited mobility. Using deuterium solid-state NMR experiments, we examine the nature of the water in the spore core. Our data show the presence of unbound water, bound water, and deuterated biomolecules that also contain labile deuterons. Deuterium–hydrogen exchange experiments show that most of these deuterons are inaccessible by external water. We believe that these unreachable deuterons are in a chemical bonding state that prevents exchange. Variable-temperature NMR results suggest that the spore core is more rigid than would be expected for a gel-like state. However, our rigid core interpretation may only apply to dried spores whereas a gel core may exist in aqueous suspension. Nonetheless, the gel core, if present, is inaccessible to external water.
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影响因子：
11.3
作者：
Higgins D;Dworkin J
通讯作者：
Dworkin J
影响因子：
3.2
作者：
Driks, A
通讯作者：
Driks, A
影响因子：
4.4
作者：
BEAMAN, TC;GERHARDT, P
通讯作者：
GERHARDT, P
影响因子：
3.9
作者：
Benesi, AJ;Grutzeck, MW;Phair, JW
通讯作者：
Phair, JW
DOI：
10.1046/j.1365-2621.1999.00240.x
发表时间：
1999-02-01
影响因子：
3.3
作者：
Ablett, S;Darke, AH;Martin, DR
通讯作者：
Martin, DR