Phase separation and liquid crystallization of complementary sequences in mixtures of nanoDNA oligomers
Articolo
Data di Pubblicazione:
2008
Citazione:
Phase separation and liquid crystallization of complementary sequences in mixtures of nanoDNA oligomers / G. Zanchetta, M. Nakata, M. Buscaglia, T. Bellini, N.A. Clark. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 0027-8424. - 105:4(2008 Jan 29), pp. 1111-1117. [10.1073/pnas.0711319105]
Abstract:
Using optical microscopy, we have studied the phase behavior of mixtures of 12- to 22-bp-long nanoDNA oligomers. The mixtures are chosen such that only a fraction of the sample is composed of mutually complementary sequences, and hence the solutions are effectively mixtures of single-stranded and double-stranded (duplex) oligomers. When the concentrations are large enough, such mixtures phase-separate via the nucleation of duplex-rich liquid crystalline domains from an isotropic background rich in single strands. We find that the phase separation is approximately complete, thus corresponding to a spontaneous purification of duplexes from the single-strand oligos. We interpret this behavior as the combined result of the energy gain from the end-to-end stacking of duplexes and of depletion-type attractive interactions favoring the segregation of the more rigid duplexes from the flexible single strands. This form of spontaneous partitioning of complementary nDNA offers a route to purification of short duplex oligomers and, if in the presence of ligation, could provide a mode of positive feedback for the preferential synthesis of longer complementary oligomers, a mechanism of possible relevance in prebiotic environments.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Condensation; Depletion; Nucleation; PEG; Prebiotic
Elenco autori:
G. Zanchetta, M. Nakata, M. Buscaglia, T. Bellini, N.A. Clark
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