Elongation/compaction of giant DNA caused by depletion interaction with a flexible polymer

被引：36

作者：

Kojima, M ^{[1
]}

Kubo, K ^{[1
]}

Yoshikawa, K ^{[1
]}

机构：

[1] Kyoto Univ, Grad Sch Sci, Dept Phys, Kyoto 6068502, Japan

来源：

JOURNAL OF CHEMICAL PHYSICS | 2006年 / 124卷 / 02期

关键词：

D O I：

10.1063/1.2145752

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Structural changes in giant DNA induced by the addition of the flexible polymer Polyethylene Glycol (PEG) were examined by the method of single-DNA observation. In dilute DNA conditions, individual DNA assumes a compact state via a discrete coil-globule transition, whereas in concentrated solution, DNA molecules exhibit an extended conformation via macroscopic phase segregation. The long-axis length of the stretched state in DNA is about 10(3) times larger than that of the compact state. Phase segregation at high DNA concentrations occurs at lower PEG concentrations than the compaction at low DNA concentrations. These opposite changes in the conformation of DNA molecule are interpreted in terms of the free energy, including depletion interaction. (c) 2006 American Institute of Physics.

引用

页数：4