OLIGONUCLEOTIDES AS PROBES FOR STUDYING POLYMERIZATION REACTIONS IN DILUTE AQUEOUS-SOLUTION

We have prepared a P-32-labeled oligonucleotide probe carrying a fre e primary amine at its 3'-terminus. This probe is used to initiate pol ymerization of aziridine (ethyleneimine) in aqueous solution. The natu re of the oligomeric products and the kinetics of their formation are then monitored by gel electrophoresis. Our results are generally consi stent with those obtained using conventional techniques. We have also investigated the effect of polyanionic templates on the rate of oligom erization of aziridine. We find that water-soluble polyanions generall y accelerate the polymerization. The sodium salt of polymethacrylic ac id is the most effective of the templates that we studied. The methods introduced in this paper should be applicable to a variety of polymer ization reactions in aqueous solution. They should greatly simplify th e screening of potentially prebiotic polymerization reactions.