Influence of Counterions on the Radius of Gyration of Phenylalanine Specific Transfer RNA as Determined by Small Angle X-Ray Studies.

The influence of the ion and water cloud shell on the structure of polyelectrolytes is very important especially for small angle studies. In the present work the change in the radius of gyration of phenylalanine specific tRNA under the influence of various counterions was investigated. tRNAPhe(yeast) was studied in different solutions at pH 7.5, each containing only one certain kind of cation. As cations lithium, cesium, barium and spermidin were used. The influence of the ions on the radius of gyration of tRNAPhe(yeast) was considerable. The value of R was 23.6 Å with Li+ ions, 26.2 Å with Cs+ ions and 26.3 Å with Ba++ ions; these resets are discussed. [ABSTRACT FROM AUTHOR]