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Preparation of DNA-crosslinked Polyacrylamide Hydrogels
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离子诱导的DNA凝中的变化
Ferenc Horkay1, Peter J Basser1, Erik Geissler2
1Section on Quantitative Imaging and Tissue Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 13 South Drive, Bethesda, MD 20892, USA. horkayf@mail.nih.gov.
Soft matter
|July 10, 2023
概括
小角度中子散射揭示了DNA凝结构如何随离子度和pH而变化. 增加化或降低pH值导致DNA凝相分离.
科学领域:
- 生物物理学的生物物理.
- 材料科学 材料科学 材料科学
- 聚合物科学 聚合物科学
背景情况:
- 基因凝是复杂的网络,其特性受到其离子环境的影响.
- 了解DNA凝的行为对于生物技术和生物材料的应用至关重要.
研究的目的:
- 通过小角度中子散射 (SANS) 在不同的离子条件下研究DNA凝的结构变化.
- 为了将离子度和pH值的变化与DNA凝网络属性和相位行为相关联.
主要方法:
- 在DNA凝上进行小角度中子散射 (SANS) 测量.
- 单价和双价对离子度和pH的变化.
- 异常小角度X射线散射 (ASAXS) 用于离子云分析.
- 测量奥斯莫斯压力.
主要成果:
- SANS数据配备了一个两项方程,考虑波动和静态不一致性.
- 低q范围的SANS表示大集群形成.
- 中间的q范围散射表明棒状结构与增加的CaCl2度.
- 高q区域的散射反映了局部链的几何结构.
- NaCl选增加了SANS强度和网格大小;CaCl2或降低的pH导致相位分离.
- 由SANS衍生的I(0) 与透压测量很好地一致.
- ASAXS显示双价离子对单价离子云的影响很弱,但聚合物链紧随着双价反离子.
结论:
- 离子强度和pH值显著改变DNA凝结构,网格大小,并可以诱导相位分离.
- SANS是描述DNA凝网络及其对环境变化的反应的强大工具.
- 对抗离子的行为对于单价离子和双价离子是不同的,影响DNA凝的特性.
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