RESUMO
We have exploited the concept of multivalency in the context of DNA recognition, using novel chemistry to synthesize a new type of bis-intercalator with unusual sequence-selectivity. Bis-intercalation has been observed previously, but design principles for de novo construction of such molecules are not known. Our compounds feature two aromatic moieties projecting from a rigid, polynorbornane-based scaffold. The length and character of the backbone as well as the identity of the intercalators were varied, resulting in mono- or divalent recognition of the double helix with varying affinity. Our lead compound proved to be a moderately sequence-selective bis-intercalator with an unwinding angle of 27 degrees and a binding constant of about 8 microM. 9-aminoacridine rings were preferred over acridine carboxamides or naphthalimides, and a rigid [3]-polynorbornane scaffold was superior to a [5]-polynorbornane. The flexibility of the linker connecting the rings to the scaffold, although less influential, could affect the strength and character of the DNA binding.
Assuntos
Acridinas/síntese química , DNA/química , Substâncias Intercalantes/síntese química , Norbornanos/síntese química , Acridinas/química , Amidas/síntese química , Amidas/química , Aminoacridinas/síntese química , Aminoacridinas/química , Desoxirribonucleases/química , Diálise , Eletroforese em Gel Bidimensional , Substâncias Intercalantes/química , Naftalimidas/síntese química , Naftalimidas/química , Norbornanos/química , Relação Estrutura-AtividadeRESUMO
Chemical formation of dehydroalanine has been widely used for the post-translational modification of proteins and peptides, however methods to incorporate multiple dehydroalanine residues into a single peptide have not been defined. We report the use of methyl 2,5-dibromovalerate which can be used to cleanly carry out this transformation.