Hydrolysis of oligoribonucleotides by alpha-helical basic peptides.

Poly(Leu-Lys-Lys-Leu) increases markedly the rate of hydrolysis of oligoribonucleotides. The polypeptide adopts and alpha-helical conformation in water in the presence of salt. Non-helical poly(Pro-Lys-Lys-Leu) is much less active. Ac-Leu-Lys-Lys-Leu-NHEt has no hydrolytic activity. Oligotetrapeptides Ac-(Leu-Lys-Lys-Leu)n-NHEt with increasing chain-length have been prepared by solid phase synthesis to evaluate the critical chain-length required for the hydrolytic activity. It is possible to correlate the activity to the propensity to form alpha-helices.