SYNTHESIS OF LONG PREBIOTIC OLIGOMERS ON MINERAL SURFACES

MOST theories of the origin of biological organization assume that pol ymers with lengths in the range of 30-60 monomers are needed to make a genetic system viable(1). But it has not proved possible to synthesiz e plausibly prebiotic polymers this long by condensation in aqueous so lution, because hydrolysis competes with polymerization. The potential of mineral surfaces to facilitate prebiotic polymerization was pointe d out long ago(2). Here we describe a system that models prebiotic pol ymerization by the oligomerization of activated monomers-both nucleoti des and amino acids. We find that whereas the reactions in solution pr oduce only short oligomers (the longest typically being a 10-mer), the presence of mineral surfaces (montmorillonite for nucleotides, illite and hydroxylapatite for amino acids) induces the formation of oligome rs up to 55 monomers long. These are formed by successive 'feedings' w ith the monomers; polymerization takes place on the mineral surfaces i n a manner akin to solid-phase synthesis of biopolymers(3,4).