DNA中的“绳上串珠”链结构。

Rings-on-a-string chain structure in DNA.

作者信息

Miyazawa Naomi, Sakaue Takahiro, Yoshikawa Kenichi, Zana Raoul

机构信息

Department of Environmental Engineering, Nagoya University, Nagoya 464-8601, Japan.

出版信息

J Chem Phys. 2005 Jan 22;122(4):44902. doi: 10.1063/1.1839860.

DOI:10.1063/1.1839860

PMID:15740293

Abstract

Using fluorescence microscopy (FM), which permits the observation of single molecules, we found that a pearling structure is generated on a single long DNA molecule upon the addition of a gemini (dimeric) surfactant. This pearling structure was further investigated by performing atomic force microscopy measurements on the same DNA molecules as observed by FM. These observations revealed that the pearling structure is composed of many rings that are interconnected by elongated coil parts along a single DNA molecule, i.e., rings-on-a-string structure. The mechanism of the formation of such an intrachain segregated structure in terms of microphase separation on a single polyelectrolyte chain is discussed.

摘要

利用能够观察单分子的荧光显微镜（FM），我们发现，在添加双子（二聚体）表面活性剂后，单个长DNA分子上会形成一种珠状结构。通过对与FM观察到的相同DNA分子进行原子力显微镜测量，对这种珠状结构进行了进一步研究。这些观察结果表明，珠状结构由许多环组成，这些环通过沿着单个DNA分子的细长螺旋部分相互连接，即串珠状结构。本文讨论了在单个聚电解质链上基于微相分离形成这种链内分离结构的机制。