Evidence for global mobility in the premelting of a polynucleotide from temperature-dependent Raman optical activity

Bell, A. F., Hecht, L. and Barron, L. D. (1998) Evidence for global mobility in the premelting of a polynucleotide from temperature-dependent Raman optical activity. Biospectroscopy, 4(2), pp. 107-111. (doi: 10.1002/(SICI)1520-6343(1998)4:2<107::AID-BSPY3>3.0.CO;2-2) (PMID:9557905)

Abstract

The backscattered Raman and Raman optical activity (ROA) spectra of poly(rA)-poly(rU) at 20°C and 45°C in buffered aqueous solution between 650 and 1750 cm−1 are reported. Although the intensity of the majority of the Raman bands increase by varying amounts as the temperature is raised in accordance with the well-known hypochromic effect, the reverse effect is found for the ROA signals which we attribute to thermal accessibility of a greater number of distinct conformations leading to cancellation of ROA signals. The difference ROA spectrum obtained by subtracting the spectrum recorded at 45°C from that recorded at 20°C displays a very similar sign pattern to those at both 20°C and 45°C throughout the spectral region examined. This indicates that the same average structure is maintained in this temperature range and that the thermal fluctuations are correlated through the bases, the glycosidic link, the sugar ring, and the phosphate backbone of both strands. These results indicate that ROA may be a useful new probe of the dynamics of nucleic acid in solution.

• Item Type: Articles
• Additional Information: The authors thank the Biotechnology and Biological Sciences Research Council for a research grant and the Engineering and Physical Sciences Research Council for a senior fellowship for L.D.B.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hecht, Dr Lutz and Barron, Professor Laurence
• Authors: Bell, A. F., Hecht, L., and Barron, L. D.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Biospectroscopy
• Publisher: Wiley
• ISSN: 1075-4261
• ISSN (Online): 1520-6343
• Published Online: 07 December 1998