Enhancement of peptide bond formation by polyribonucleotides on clay surfaces in fluctuating environments

Summary

The condensation of glycine to form oligoglycine during temperature and moisture fluctuations on clay surfaces was enhanced up to fourfold by polyribonucleotides. Polydeoxyribonucleotides gave no enhancement. Yields were greatly reduced in the absence of clay. A small preference was observed among the polyribonucleotide bases with enhancements in the order of Poly G > Poly A = Poly U > Poly C at high density of polynucleotide on the clay surface and Poly G > Poly U > Poly C > Poly A at low density. This and other experiments seem to indicate a codonic bias in the interaction of polynucleotides with amino acids reacting to form peptide bonds. A mechanism is proposed which involves (1) activation of glycine on the clay surface, (2) formation of esters between glycine and the 2′-OH groups of the polyribonucleotide, and (3) formation of peptide bonds between adjacent amino acyl esters. If this mechanism is correct, it may provide the basis for a simple, direct-template translation process.