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arXiv 1512.08074q-bio.BM
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通过比较广角X射线散射(WAXS)实验和分子动力学模拟来理解核酸结构变化

Understanding Nucleic Acid Structural Changes by Comparing Wide-Angle X-ray Scattering (WAXS) Experiments to Molecular Dynamics Simulations

Suzette A. Pabit, Andrea M. Katz, Igor S. Tolokh, Aleksander Drozdetski, Nathan Baker, Alexey V. Onufriev, Lois Pollack

摘要:

广角X射线散射(WAXS)是一种提高生物分子溶液结构测量分辨率的有力工具。与其更知名的补充,小角X射线散射(SAXS)相比,WAXS的目标是更高的散射角,可以通过访问溶液结构的更精细的细节来增强分子的结构研究。虽然从SAXS到WAXS的扩展很容易在实验上实现,但完全利用WAXS的能力所需的计算工具仍在开发中。目前,WAXS用于研究蛋白质的结构变化和配体结合;然而,该方法尚未完全开发用于核酸。在这里,我们展示了WAXS如何定性地表征核酸结构以及由添加多价离子驱动的小但显着的结构变化。我们展示了WAXS测试全原子分子动力学(MD)模拟的潜力,并为理解三价离子钴(III)六胺合物(CoHex)如何影响RNA和DNA螺旋结构提供了见解。我们发现,MD模拟捕捉到的RNA结构的变化,由于添加CoHex。

英文摘要:

Wide-angle x-ray scattering (WAXS) is emerging as a powerful tool for increasing the resolution of solution structure measurements of biomolecules. Compared to its better known complement, small angle x-ray scattering (SAXS), WAXS targets higher scattering angles and can enhance structural studies of molecules by accessing finer details of solution structures. Although the extension from SAXS to WAXS is easy to implement experimentally, the computational tools required to fully harness the power of WAXS are still under development. Currently, WAXS is employed to study structural changes and ligand binding in proteins; however the methods are not as fully developed for nucleic acids. Here, we show how WAXS can qualitatively characterize nucleic acid structures as well as the small but significant structural changes driven by the addition of multivalent ions. We show the potential of WAXS to test all-atom molecular dynamics (MD) simulations and to provide insight in understanding how the trivalent ion cobalt(III) hexammine (CoHex) affects the structure of RNA and DNA helices. We find that MD simulations capture the RNA structural change that occurs due to addition of CoHex.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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