The non-enzymatic hydrolysis of oligoribonucleotides VI. The role of biogenic polyamines

Abstract

Single-stranded oligoribonucleotides containing UA and CA phosphodiester bonds can be hydrolyzed specifically under non-enzymatic conditions in the presence of spermidine, a biogenic amine found in a wide variety of organisms. In the present study, the rate of oligonucleotide and tRNA(i)(Met)hydrolysis was measured in the presence of spermidine and other biogenic amines. It was found that spermine [H(3)N(+)(CH(2))(3)(+)NH(2)(CH(2))(4)(+)NH(2)(CH(2))(3)(+)NH(3)] and putrescine [H(3)N(+)(CH(2))(4)(+)NH(3)] can replace spermidine [H(3)N(+)-(CH(2))(4)(+)NH(2)(CH(2))(3)(+)NH(3)] to induce the hydrolysis. For all three polyamines, a bell-shaped cleavage rate versus concentration relationship was observed. The maximum rate of hydrolysis was achieved at 0.1, 1.0 and 10 mM spermine, spermidine and putrescine, respectively. Moreover, we found that the hydrolysis requires at least two linked amino groups since two aminoalcohols, 2-aminoethanol and 3-aminopropanol, were not able to induce the cleavage of the phospho-diester bond. The optimal cleavage rate of the oligo-ribonucleotides was observed when amino groups were separated by tri- or tetramethylene linkers. The methylation of the amino groups reduced the ability of diamines to induce oligoribonucleotide hydrolysis. Non-enzymatic cleavage of tRNA(i)(Met)from Lupinus luteus and tRNA(i)(Met)from Escherichia coli demonstrate that both RNAs hydrolyze as expected from principles derived from oligoribonucleotide models.

Structural Considerations Concerning Cleavage of RNA

“…Presumably, the methyl substituent decreases the ability of the 6-amino group to form a hydrogen bond with the other part of the scissile internucleotide bond, perhaps the phosphorus center. This is consistent with the observation that Ut6A (t 6 A=N6-[N-threonylcarbonyl]-adenosine) is stable in the anticodon loop of tRNAjMet from Lupinus luteus, whereas UA is unstable in the anticodon loop of tRNAjMet from Escherichia coli (Bibillo et al 1999b). …”

“…To extend the structural requirements for spontaneous cleavage, the stability of hairpins and tRNA were studied as well (Bibillo et al 1999b;Bibillo et al 2001).…”

Borate Minerals and RNA Stability

“…The relatively high stability of the PolyA sequence in aqueous solution is well established [18][19][20]. The stability of RNA phosphodiester bonds has repeatedly been associated with the stacking interactions between adjacent bases [21][22][23]. Nucleic acid base-stacking is at present an understood phenomenon [24][25][26][27][28].…”

Adaptive role of increased frequency of polypurine tracts in mRNA sequences of thermophilic prokaryotes

“…Also important to the overall rate of protein synthesis is the stability of the mRNAs to spontaneous hydrolysis by intramolecular transesterification. It is noteworthy that hydrolysis is elevated dramatically at high temperature but might depend on the RNA-specific sequence organization (37)(38)(39)(40).…”