Spontaneous self-assembly of nucleic acids: liquid crystal condensation of complementary sequences in mixtures of DNA and RNA oligomers
Articolo
Data di Pubblicazione:
2009
Citazione:
Spontaneous self-assembly of nucleic acids: liquid crystal condensation of complementary
sequences in mixtures of DNA and RNA oligomers / G. Zanchetta. - In: LIQUID CRYSTALS TODAY. - ISSN 1358-314X. - 18:2(2009 Oct 07), pp. 40-49. [10.1080/13583140903155093]
Abstract:
A remarkable example of spontaneous self-assembly of biomolecules, driven purely by physical interactions, is
reported. Short, complementary DNA and RNA oligomers, down to six bases in length, exhibit lyotropic liquid
crystal phases, chiral nematic and columnar, although these duplexes lack the shape anisotropy required for liquid
crystal ordering. Such phases are produced by the end-to-end stacking of the duplex oligomers into polydisperse,
anisotropic, rod-shaped aggregates, which can order into liquid crystals. Furthermore, when only a fraction of the
sample is composed of complementary sequences, and hence the solution is effectively a mixture of single strands
and double-stranded helices, the system is found to phase separate with duplex-rich liquid crystalline domains
emerging from an isotropic background rich in single strands. This spontaneous partitioning, resulting from a
combination of entropic and enthalpic factors, is sensitive to the degree of complementarity of the sequences and
can be tuned with temperature. We suggest that in a chemical environment where oligomer ligation is possible, such
ordering and condensation could provide a plausible route for the selective synthesis of extended complementary
oligomers, a mechanism of possible relevance in prebiotic scenarios.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
DNA ; RNA ; nucleic acids ; stacking ; chromonics ; phase transitions ; Onsager ; nucleation ; depletion ;
prebiotic ; ribozyme ; ligation
Elenco autori:
G. Zanchetta
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