No abstract

The faithful recognition of the interstrand hydrogen bonds between complementary nucleobases forms the foundation of the genetic code. The ability to replicate DNA containing a stable third base pair would allow for an expansion of the information content of DNA by supplementing the existing two base pairs of the genetic alphabet with a third. We report the optimization of unnatural nucleobases whose pairing in duplex DNA is based on interbase hydrophobic interactions. We show that the stability and selectivity of such unnatural base pairs may be comparable to, or even exceed, that of native pairs. We also demonstrate that several unnatural base pairs are incorporated into DNA by Klenow fragment of Escherichia coli DNA polymerase I with an efficiency equivalent to that of native DNA synthesis. Moreover, the unnatural bases are orthogonal to the native bases, with correct pairing being favored by at least an order of magnitude relative to mispairing.

A novel strategy for the preparation of peptidic-synthetic bioconjugate block copolymers is based upon sequential condensation and living radical addition polymerizations, each performed upon a solid support.

No abstract

Hybrid peptidic-synthetic amphiphilic block copolymers, synthesized by living free radical polymerization (LFRP) on solid support, have been utilized as precursors for nanoscale materials possessing bio-available peptides. LFRP initiators, coupled to the peptide terminus upon the resin, facilitated the growth of homo- and block copolymers via nitroxide mediated radical polymerization (NMRP) or atom transfer radical polymerization (ATRP). Herein, the versatile solid-support synthesis of the antimicrobial peptide tritrpticin, coupling of living free radical polymerization initiators to the peptide-loaded resin, and the controlled radical polymerization of various monomers to yield amphiphilic diblock copolymers are described. Assembly of the peptidic-synthetic block copolymers into micelles and a preliminary assessment of their in vitro biological properties are detailed.