ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
RNA oligomers with the sequence An-U-G-Um, n = 7-9, m = 5-10, have been synthesized and found to form hairpin loops in 21 mM or 101 mM Na+. The hairpin loops displayed melting temperatures 13°-29°C greater than that of the hairpin loop A6-C8-U6 in the same solvent. The increased stability of these hairpin loops is attributed to the presence of the trinucleotide A-U-G in the loop.Circular dichroism (CD) spectra were taken of the hairpin loops A7-U-G-U6,7,8, A8-U-G-U6,7,8, and A9-U-G-U6 in 21 mM Na+, and compared with circular dichroism spectra of A6-U6 in 1 M Na+. Difference spectra were calculated between each An-U-G-Um and 11.5 mM (nucleotide) A6-U6 at similar temperatures and identical singlestrand fractions to give the “experimental” CD spectrum of the unbase-paired nucleotides in the loop, assuming, five, six, or seven base pairs. CD spectra were calculated for each of the assumed unbase-paired sequences using the measured CD spectra of ApA, A-U-G-, A, and U, and compared with the experimental spectra. The best agreement was found for hairpin-loop models containing five base pairs and five to eight unbase-paired nucleotides in the loop.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1974.360131116
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