Isoprenylation of transfer ribonucleic acid

A two-fold difference in the total N⁶-(Δ²-isopentenyl) adenosine content was found between the serine accepting tRNA fractions from adult and embryonic bovine liver. Elution profiles of benzoylated DEAE cellulose showed three peaks of adult tRNA were capable of accepting serine. Using gas-liquid chromatography, each peak had measurable amounts of N⁶-(Δ²-isopentenyl) adenosine. When the same techniques were applied to embryonic bovine tRNA, three peaks accepted serine; however, only one peak contained N⁶-(Δ²-isopentenyl) adenosine. These results can be interpreted to indicate that adult and embryonic tRNA differ in the N⁶-(Δ²-isopentenyl) adenosine content of tRNA^ser.     

Helical regions in transfer ribonucleic acid

Summary By following the thermal denaturation of transfer RNA (t-RNA) over a wide wavelength range it can be demonstrated that t-RNA dissociates in at least two steps. The lower melting step seems to melt cooperatively, while this can not be stated with confidence about the higher melting region. It is shown that the use of difference spectra of two-stranded transitions gives similar, but different results than the use of difference spectra for three stranded-transitions. It is thus shown that difference spectra can not be used (at least at present) to distinguish strandedness in RNA. Possible applications of the method of difference spectra are discussed.