ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The optical density-temperature profile of double-stranded poly(A + U), triple stranded poly(A + 2U), and double-stranded RNA from rice dwarf virus in solutions with and without poly-L-lysine has been examined. When poly-L-lysine is added, more than one melting temperature Tm is observed for poly(A + U) and poly(A + 2U). One of them is considered to correspond to the melting of the polynucleotide molecule free from poly-L-lysine, and another to the melting of a polynucleotide-poly-L-lysine complex. For rice dwarf virus RNA, the Tm assignable to the complex is not found to be lower than 99°C. In every case, however, the hyperchromicity observed at the Tm of the free poly-nucleotide molecule is lowered linearly as the amount of poly-L-lysine added to the solution increases. This fact is taken as indicating that there is a stoichiometric complex formed. The stoichiometric ratio lysine/nucleotide in each complex is determined by examining the relation between the amount of poly-L-lysine added to the solution and the percentage of hyperchromicity remaining at Tm of the free polynucleotide molecule. The ratio is found to be 2/3 for all of the three complexes. A discussion is given on the molecular conformations of four types of polynucleotide-polylysine complex hitherto found: (A) double-stranded DNA plus poly-L-lysine in which the lyslne/nucleotide ratio is 1, (B) three-stranded RNA [poly(A + 2U)] plus poly-L-lysine in which the ratio is 2/3, (C) double-stranded RNA [poly (A + U) or rice dwarf virus RNA] plus poly-L-lysine in which the ratio is 2/3, and (D) double-stranded RNA [poly(I + C)] plus poly-L-lysine in which the ratio is 1/2.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1966.360040804
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