Polypeptide-assisted oligomerization of analogs in dilute aqueous solution

Poly (Leu-Lys) was shown to assist the oligomerization of activated nucleotide diphosphates. Short oligomers of pdGp are formed in dilute solution. Activated oligomers can complex to the polypeptide and polymerize to form longer oligomers. Oligomers up to the 18-mer can be obtained under these conditions from 1 × 10^–3 M ImpdGpIm in the absence of a preformed polynucleotide template. The total yield of polymerization remains limited although 50% more pyrophosphate bonds are formed in the presence of polypeptide. However, the elongation effect is more significant since the yield of oligomers longer than the decamer is increased by a factor of 60. The possible prebiotic implications of these experiments are discussed.Abbreviations pdGp the 3,5-bisphosphate of dG - ImpdGpIm the 3,5-bisphosphoimidazolide of dG - KEDTA ethylenediamine tetraacetic acid, potassium salt - Bis-Tris bis(2-hydroxymethyl)iminotris(hydroxymethyl)methane Correspondence to: B. Barbier