We have recently shown that solutions of very short double-stranded B-DNA and A-RNA, down to six base pairs in length, can self-organize into chiral nematic and columnar liquid crystal (LC) phases. These observations were made on fully complementary sequences forming duplexes with blunt ends, where the LC ordering is due to base stacking forces promoting end-to-end aggregation of duplexes into living-polymer-type structures. Here we report LC formation in solutions of DNA and RNA 14mers forming double helices having single-stranded dangling ends that are ‘sticky’, i.e., mutually complementary with similar ends on other duplexes. This finding widens the conditions for spontaneous long range ordering in oligomeric nucleic acids, thus strengthening the notion that nucleic acids have remarkable self-assembly capability. Quantitative analysis of the phase diagram enables the extraction, within a nearest-neighbor interaction approximation, of the free energy associated with the pairing and stacking of nucleobases.
Liquid crystal ordering of DNA and RNA oligomers with partially overlapping sequences / G. Zanchetta, M. Nakata, M. Buscaglia, N.A. Clark, T. Bellini. - In: JOURNAL OF PHYSICS. CONDENSED MATTER. - ISSN 0953-8984. - 20:49(2008), pp. 494214.494214-1-494214.494214-6.
Liquid crystal ordering of DNA and RNA oligomers with partially overlapping sequences
G. ZanchettaPrimo
;M. Buscaglia;T. BelliniUltimo
2008
Abstract
We have recently shown that solutions of very short double-stranded B-DNA and A-RNA, down to six base pairs in length, can self-organize into chiral nematic and columnar liquid crystal (LC) phases. These observations were made on fully complementary sequences forming duplexes with blunt ends, where the LC ordering is due to base stacking forces promoting end-to-end aggregation of duplexes into living-polymer-type structures. Here we report LC formation in solutions of DNA and RNA 14mers forming double helices having single-stranded dangling ends that are ‘sticky’, i.e., mutually complementary with similar ends on other duplexes. This finding widens the conditions for spontaneous long range ordering in oligomeric nucleic acids, thus strengthening the notion that nucleic acids have remarkable self-assembly capability. Quantitative analysis of the phase diagram enables the extraction, within a nearest-neighbor interaction approximation, of the free energy associated with the pairing and stacking of nucleobases.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.