Polyriboadenylic acid

Petrovic AG, Polavarapu PL (2005) Structural transitions in polyriboadenylic acid induced by the changes in pH and temperature vibrational circular dichroism study in solution and film states. J Phys Chem B 109 23698-23705... 

Fig. 7.5. Some typical molecular weiglit-mobility (or sedimentation coefficient) relationstiips for electrophoresis of RNA in polyacrylamide gels, showing conformational effects a) set of single-stranded viral and ribosomal RNAs in 2.4% gel (Bishop et al. 1967). b) shows a typical separation of different species on a single gel, displayed as a densitometric trace c) native single-stranded RNAs ( ), formaldehyde treated RNAs (O). polyriboadenylic acid fractions with (A) and without (A) formaldehyde treatment, and polyribouridylic acid fractions ( ) treated with formaldehyde. These data show that the mobilities are little affected by single-stranded stacking, but substantially by partial base pairing, and that formaldehyde treatment is inadequate to reduce RNA to the conformation of a single-stranded unpaired polynucleotide (from Finder et al., 1974).

Fig. 7.18. Molecular weight-mobility relationships for a series of RNA species ( ) polyriboadenylic acid fractions (O) and polyribouridylic acid fractions (f)) in formamide gels (Finder, Staynov and Gratzer).

Delayed fluorescence in a rigid matrix proves triplet excitons if other delayed S- —+So emissions, as high temperature phosphorescence or ionisation followed by ion-electron recombination can be excluded (15). The delayed fluorescence observed in solid solutions of Polyriboadenylic acid (45) seems to be due to this latter process (78). 

A tail of polyriboadenylic acid, poly (A), as much as 200 bases long, is added by a special non-template-directed polymerase. The function of the poly(A) tails of eukaryotic mRNAs is unknown. They cannot be essential for all messages, however, because some mRNAs (for example, most histone mRNAs in higher eukaryotes) do not have them. One idea is that they relate to message stability, because the tail-less messages typically have much shorter lifetimes in the nucleus. 

ENTHALPY OF STACKING IN SINGLE-STRANDED POLYRIBOADENYLIC ACID. 

J. R. Fresco and E. Klemperer Polyriboadenylic acid, a molecular analogue... 

Abbreviations A, absorbance BSS, Hank s balanced salt solution max, maximal wavelength min, minimal wavelength O.D., optical density poly A, polyriboadenylic acid poly C, polyribocytidylic acid poly G, polyriboguanidylic acid poly U, polyribouridylic acid UV, ultraviolet rays. 

The nomenclature is the standard lUPAC-lUB one [79il] although the poly or the subscript n have been omitted. Thus r(A) stands for r(A) or poly(A) or polyriboadenylic acid, d(T) stands for poly-deoxyribo-5-methyl-uridylic acid or poly-thymidylic acid. 

Macro radical formed from H-atom abstraction by 6h radicals from 2 -position of the sugar moiety for polyriboadenylic acid (Mw = 6.3-10 ). 

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