DNA-directed coupling of organic modules by multiple parallel reductive aminations and subsequent cleavage of selected DNA sequences

A new method for DNA-directed assembly of organic modules by multiple parallel reductive aminations is presented. Linear oligonucleotide-functionalized modules (LOMs) consist of a rigid oligo(phenylene ethynylene) backbone with two salicylaldehyde termini, and each terminus is conjugated with an oligonucleotide sequence. The stability of the tetrahydrosalen-linked modules toward elevated temperature, low pH, nucleophiles, and metal chelators is studied and compared to the analogous metal-salen-linked modules. A linear oligonucleotide-functionalized disulfide-linked module (LOSM) containing cleavable linkers between the organic module and the two DNA sequences is coupled by DNA-directed reductive aminations to non-modified LOM modules. This enables selective cleavage of the DNA strands of a central module in a structure consisting of three modules, and the reactions are analyzed by electrophoresis and 32P-labeling of one of the DNA sequences of the central LOSM.