Effects of crowding on the stability of a surface-tethered biopolymer: an experimental study of folding in a highly crowded regime.
Effects of crowding on the stability of a surface-tethered biopolymer: an experimental study of folding in a highly crowded regime.
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DOI：
10.1021/ja411486g
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发表时间：
2014-06-25
影响因子：
15
通讯作者：
Plaxco KW
中科院分区：
文献类型：
--
作者：
Watkins HM;Simon AJ;Ricci F;Plaxco KW
生物分子可以附着到宏观表面的高堆积密度和固定几何形状表明，在这些通常密集堆积的条件下，拥挤效应可能特别显著。探索这个问题的实验，我们在这里报告拥挤的影响，一个简单的，表面附着的DNA茎环的稳定性。我们发现，拥挤的密集包装，折叠的生物分子不稳定我们的测试床生物分子由102 kJ/mol相对于稀释（非相互作用）制度，这种效果可能是由于空间和静电排斥所产生的紧凑的邻居。相比之下，被未折叠的生物分子的密集刷所拥挤，使其稳定性提高了106 kJ/mol，这可能是由于排除的体积和静电效应降低了未折叠状态的熵。最后，相同生物分子的相似拷贝的拥挤产生显著更宽的解折叠转变，可能是因为在这些情况下，随着越来越多的邻居解折叠，解折叠分子的拥挤的稳定效应增加（并且相邻折叠分子的不稳定效应减少）。因此，表面附着的生物分子的拥挤可能是一个更丰富，更复杂的现象比均匀的溶液中看到的。
The high packing densities and fixed geometries with which biomolecules can be attached to macroscopic surfaces suggest that crowding effects may be particularly significant under these often densely packed conditions. Exploring this question experimentally, we report here the effects of crowding on the stability of a simple, surface-attached DNA stem-loop. We find that crowding by densely packed, folded biomolecules destabilizes our test-bed biomolecule by ∼2 kJ/mol relative to the dilute (noninteracting) regime, an effect that presumably occurs due to steric and electrostatic repulsion arising from compact neighbors. Crowding by a dense brush of unfolded biomolecules, in contrast, enhances its stability by ∼6 kJ/mol, presumably due to excluded volume and electrostatic effects that reduce the entropy of the unfolded state. Finally, crowding by like copies of the same biomolecule produces a significantly broader unfolding transition, likely because, under these circumstances, the stabilizing effects of crowding by unfolded molecules increase (and the destabilizing effects of neighboring folded molecules decrease) as more and more neighbors unfold. The crowding of surface-attached biomolecules may thus be a richer, more complex phenomenon than that seen in homogeneous solution.
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影响因子：
3.4
作者：
Qin, Sanbo;Zhou, Huan-Xiang
通讯作者：
Zhou, Huan-Xiang
DOI：
10.1038/nsb1001-879
发表时间：
2001-10-01
期刊：
NATURE STRUCTURAL BIOLOGY
影响因子：
--
作者：
Ghaemmaghami, S;Oas, TG
通讯作者：
Oas, TG
影响因子：
3.8
作者：
Chatake, Toshiyuki;Sazaki, Gen;Morimoto, Yukio
通讯作者：
Morimoto, Yukio
影响因子：
3.8
作者：
Qu, YX;Bolen, DW
通讯作者：
Bolen, DW
DOI：
10.1073/pnas.0535055100
发表时间：
2003-03-04
影响因子：
11.1
作者：
Elcock, AH
通讯作者：
Elcock, AH