ISSN:
0173-0835
Keywords:
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Double-stranded (ds) RNA normally exhibits a lower electrophoretic mobility than dsDNA having the same number of base pairs. This has been attributed to its net charge density that is lower than that of B-form DNA. But we show here that dsRNA runs faster than corresponding DNA in gels containing either ≥ 2.5% agarose or ≥ 8% acrylamide with high crosslinking (19:1 acryl-amide: N,N′-methylenebisacrylamide). However, the relative mobility of dsRNA as compared with DNA, extrapolated to 0% gel (0%T), remains constant (0.90 ± 0.03) in all systems, in support of the charge density hypothesis. In comparison to dsRNA standards, the potato spindle tuber viroid, a small ≍ 70% base-paired rod-like pathogenic RNA, is strongly retarded, presumably because of greater flexibility and/or stable curvature. Depending on the gel system, nonlinear extrapolation to 0% T leads to an apparent contour length of 140-230 bp, whereas 130 ± 20 bp can be determined from electron micrographs and 123-126 bp from secondary structure modeling. We attribute the variation of the electrophoretic behavior of both dsRNA and viroid RNA to interactions with the gel matrix. Nevertheless, extrapolation of the apparent contour length (in bp dsRNA) determined from low-crosslinked polyacryl-amide gels (2.6%C) is comparable to the determination by alternative methods.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elps.11501501213
