Nonenzymatic hydrolysis of oligoribonucleotides. V. The elements affectingthe process of self-hydrolysis

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