With support from the Organic Synthesis Program, Professor James P. Ferris studies the synthesis of ribonucleic acids on minerals. This work, carried out in the Department of Chemistry at Rensselaer Polytechnic Institute, focuses on clay mineral-mediated formation of phosphodiester linkages between ribonucleotides. Suites of RNA oligomers containing random sequences of thirty to fifty bases with a high proportion of 3',5'-phosphodiester linkages are produced via RNA primer elongation on montmorillonite clay. These oligomers are tested for catalytic activity in order to provide a laboratory demonstration of the transition from prebiotic chemistry to catalytic activity as postulated by the RNA world scenario for the origins of life. Clay-catalyzed synthesis of homochiral RNAs from racemic nucleotides is also explored, helping to shed light on the origins of chirality. Plausible activating groups for the synthesis of RNA on mineral surfaces are chosen to represent those likely to have been prevalent under primitive earth conditions, and inhibitor studies are carried out in order to help direct the search for other minerals with comparable or superior catalytic capabilities. Many unanswered questions remain about the origins of life, beginning at the very basic chemical level of how the first catalysts (materials which facilitate the reactions of other molecules) evolved. Professor Ferris examines the role of clay minerals in catalyzing the formation of molecules representing the possible precursors to life, focusing on the synthesis of ribonucleic acids (RNA) which in turn may function as catalysts for the synthesis of still more complex molecules. These studies also address the fundamental question of how life's molecules acquired the unique structural feature of chirality, wherein many biologically active molecules display a three-dimensional structure distinct from that of their mirror image (just as a right hand differs from a left hand).
