This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.106.094185v1 92/4/1318    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zinchenko, A. A. Articles by Yoshikawa, K. Search for Related Content PubMed PubMed Citation Articles by Zinchenko, A. A. Articles by Yoshikawa, K.

Transcription of Giant DNA Complexed with Cationic Nanoparticles as a Simple Model of Chromatin

Graduate School of Science, Department of Physics, Kyoto University, Sakyo-ku, Kyoto 608-8501, Japan; and "Spatio-Temporal Order" Project, International Collaboration Research Project, Japan Science and Technology Agency, Tokyo, Japan

Correspondence: Address reprint requests to Anatoly A. Zinchenko, E-mail: zinchenko{at}urban.env.nagoya-u.ac.jp.

We prepared complexes of giant double-stranded DNA with cationic nanoparticles of 10–40 nm in diameter as an artificial model of chromatin and characterized the properties of changes in their higher-order conformation. We measured the changes in transcriptional activity that accompanied the DNA conformational transitions. Complete inhibition was found at excess concentrations of nanoparticles. In contrast, at intermediate stages of DNA binding with nanoparticles, the transcription activity of DNA survived, and this strongly depended on the size of the nanoparticles. For large nanoparticles of 40 nm, a decrease in transcriptional activity can be caused by the addition of only a small amount of nanoparticles. On the other hand, there was almost no inhibition of DNA transcriptional activity with the addition of small nanoparticles (10 nm) until very high concentrations, even under conditions that induced DNA compaction as revealed by single-DNA observation. At higher concentrations of 10-nm nanoparticles, DNA transcription activity decreased abruptly until it was completely inhibited. These results are discussed in relation to the actual size of the histone core, together with the mechanism of switching of transcriptional activity in eukaryotic cells.

This article has been cited by other articles:

				S. Lindsay Chromatin Control of Gene Expression: The Simplest Model Biophys. J., February 15, 2007; 92(4): 1113 - 1113. [Full Text] [PDF]