CONFORMATION-CONTROLLED HYDROLYSIS OF POLYRIBONUCLEOTIDES BY SEQUENTIAL BASIC POLYPEPTIDES

Polycationic polypeptides containing basic and hydrophobic amino acids strongly accelerate the hydrolysis of oligoribonucleotides. We have examined aspects of the oligonucleotide-polypeptide interaction, as well as the relationship among amino acid composition, polypeptide conformation, and the hydrolytic effect. We conclude that, to be active, the polypeptides must present a regular distribution in space of basic groups (beta-sheet or alpha-helix). A tentative model is given involving an alignment of the polynucleotidie chain between two parallel rows of positive charges. The experimental data for the base-induced hydrolysis are consistent with a mechanism involving two basic amino acid side chains,