| The long-term goal of this work is to use the control afforded by nucleic acids to direct the topology of polymers of industrial importance. The synthesis of "nylon-DNA," a ladder polymer with oligoamide and oligonucleotide rails and dialkylsulfide rungs, was demonstrated previously. This thesis describes the chemical separation of the two rails of nylon-DNA into individual oligomeric components and the expansion of nylon-DNA to include nucleobases besides uridine.; Chapter 2 describes the release of coupled oligoamides from a nucleic acid template. Phosphoramidite reagents were prepared containing pendant moieties as chain propagating and chain terminating groups for amide polymerization. Automated DNA synthesis produced oligomers with two or four modified uridine nucleotides that were coupled with a chemical coupling reagent. The resulting nylon-DNA ladder polymer was cleaved into nucleic acid and amide oligomers by reductive desulfurization with Raney nickel.; DNA-directed polymer assembly eventually will require DNA strands containing all four nucleobases, but previous work has been limited to uridine derivatives. Chapter 3 describes the preparation and properties of nylon-DNA containing both modified uridine and cytidine nucleotides. Modified cytidine phosphoramidite reagents were synthesized. DNA strands containing modified cytidine monomers as well as modified uridine reagents were prepared. The stability and structure of nylon-DNA duplexes with complementary DNA strands were examined. Thermal denaturing studies of a series of oligonucleotides containing nylon-DNA and corresponding synthetic precursor strands revealed that the amide linkage can significantly enhance the binding affinity of nylon-DNA towards complementary DNA when compared with non-amide linked precursor strands. Chapter 4 gives a synthetic strategy for modification of adenosine. An important intermediate compound, 2'-deoxy-2'-mercaptoadenosine, was achieved. |
