Confinement driven spatial organization of semiflexible ring polymers: Implications for biopolymer packaging
Confinement driven spatial organization of semiflexible ring polymers: Implications for biopolymer packaging
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DOI：
10.1039/c1sm05445g
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发表时间：
2011-01-01
期刊：
影响因子：
3.4
通讯作者：
Heermann, Dieter W.
中科院分区：
文献类型：
--
作者：
Fritsche, Miriam;Heermann, Dieter W.
研究了半柔性环状聚合物在有限空间中的构象性质。考虑到构型熵，弯曲能和排除体积之间的相互作用，我们阐明了不同的几何约束可以发挥的作用，在塑造生物聚合物的空间组织。虽然细长的，棒状的几何形状减少链越越的量，并诱导相对于周围的信封的长轴的一个明显的顺序，存在没有优选的取向轴的情况下，球形限制。在增加系统密度和链的刚性时，聚合物从可接近空间的中心向周围表面迁移，形成已知用于病毒衣壳内DNA缩合的线轴状结构。不同限制几何形状的区别环大小的存在可能会影响基因表达的全基因组协调所必需的生物聚合物中的共定位。因此，某些几何约束的优势，如病毒DNA在衣壳中的球形限制或大肠杆菌环状染色体的杆状包膜，可能是控制适当生物功能的一种驱动力。
We investigate the conformational properties of a semiflexible ring polymer in confined spaces. Taking into account the competing interplay between configurational entropy, bending energy and excluded volume, we elucidate the role that different geometrical constraints can play in shaping the spatial organization of biopolymers. While elongated, rod-like geometries reduce the amount of chain overcrossings and induce a pronounced ordering with respect to the long axis of the surrounding envelope, there exists no preferred orientational axis in the case of spherical confinement. Upon increasing the system density and the rigidity of the chain, the polymer migrates from the center of the accessible space towards the surrounding surface, forming a spool-like structure known for DNA condensation within viral capsids. The existence of distinguished loop sizes for different confining geometries might influence co-localization in biopolymers necessary for the genome-wide coordination of gene expression. Thus, the advantages of certain geometric constraints, such as spherical confinement of viral DNA in a capsid or the rod-shaped envelope of the circular chromosome in Escherichia coli could be one driving force for controlling proper biological functioning.