[Reactivity of the 3'-terminal oligonucleotide Sequence C-A-C-C-A of tRNAPhe and tRNAVal from baker's yeast upon N-oxidation with monoperphthalic acid as compared to the oligonucleotides C-A-C-C-A and A-A-A-U-C-A-C-C-A (author's transl)].

The nucleobases adenine and cytosine were subjected to N-oxidation by monoperphthalic acid at pH 7 and 0 degrees C in tRNAPhe, in the 3'-terminal pentanucleotide C-A-C-C-A from tRNAPhe, as well as in tRNAVal and in the 3'-terminal nonanucleotide A-A-A-U-C-A-C-C-A from tRNAVal. In the tRNAs, the oxidative attack occurs stepwise from the 3'-end. First the 3'-terminal adenine is oxidized, then the following two cytosines, then the following adenine. The oligonucleotides are far more reactive than the identical sequences in tRNA and are not oxidized according to a sequential mechanism.