壳聚糖与DNA相互作用的单分子方法研究  

Single molecular analysis of the interaction between DNA and chitosan

作　　者：张旭[1] 王艳伟[1] 杨光参[1] 

机构地区：[1]温州大学物理与电子信息工程学院,浙江温州325035

出　　处：《山东科学》2014年第3期1-6,共6页Shandong Science

基　　金：国家自然科学基金(11274245;10974146);浙江省自然科学基金(Y6090222)

摘　　要：利用原子力显微镜与磁镊技术研究不同浓度的壳聚糖与多种DNA分子的作用,对其凝聚形态及力谱曲线进行观察.在恒力情况下,壳聚糖与DNA的电荷比k分别为3和4时,从DNA的力谱曲线上可以看见0.2～0.5 μm左右的跳跃阶梯及线性增长区域,原因可能是壳聚糖-DNA聚合物中出现了环状、棒状及球状结构;利用原子力显微镜观察壳聚糖与λ-DNA及bpr322-DNA作用后的凝聚形态,发现随着壳聚糖与DNA电荷比k的增加,球状与棒状聚合物的比例明显减小,而且凝聚物的尺寸也整体减小.最后根据实验结果,建立了壳聚糖导致DNA构象变化的直观模型.We applied an atomic force microscopy（AFM）and a single molecular magnetic tweezer（MT） to the interaction between DNA and chitosan of different concentrations.We investigated their condensed morphologies and time dependent force curves.0.2 to 0.5 μm steps and linear incremental area would appear from the DNA force curves for the MT experiment when the charge ratio of chitosan and DNA （k） is 3 and 4.The phenomenon may come from the circular,rod and spherical structures of DNA-chitosan complexes.We also employed AFM to observe the condensed morphologies due to the interaction between λ-DNA or bpr322-DNA and chitosan.The proportion of spherical and rod structures and the size of condensates significantly decreased with the increase of k.We eventully constructed a concrete model of DNA morphology variety caused by chitosan.

关 键 词：壳聚糖 DNA 磁镊 原子力显微镜 

分 类 号：Q78[生物学—分子生物学]