Interstrand interactions on DNA duplexes modified by TTF units at the 3′ or 5′-ends

Short DNA duplexes carrying TTF units at the same termini exhibit a high increase in melting temperature. When both TTF units were on opposite termini, salt-dependent aggregation is observed, yielding well defined spherical DNA supramolecular structures.This research was supported by the European Commission under Grant No. FP7-FUNMOL 213382, by the Spanish Ministry of Education (CTQ2010-20541), the Generalitat de Catalunya (2009/SGR/208), the Czech Science Foundation (P207/10/2214) and the Institute of Organic Chemistry and Biochemistry AS CR (this work is part of the Research Project Z4 055 0506). Dr. Radek Pohl is acknowledged for the NMR spectra measurement as well as the electron cryo-microscopy unit from CCiT of University of Barcelona for the use of the EM facility.Peer reviewe