Nonenzymatic hydrolysis of oligoribonucleotides. V. The elements affecting the process of self-hydrolysis

Chemical instability of some of the phosphodiester bonds, often observed in large RNAs, visualizes the autocatalytic properties of this class of nucleic acids. Unexpectedly, selective hydrolysis occurs also in short oligoribonucleotides (as short as a tetramer or hexamer). Herein, we describe additional experiments which support the conclusion that the hydrolysis is not due to ribonuclease contamination but is of autocatalytic origin and is related to the sequence and structure of single-stranded oligomers. Moreover, we show that the presence in the reaction mixture of polyamines, such as spermidine, is essential for hydrolysis of oligoribonucleotides.