Branched oligonucleotide‐intercalator conjugate forming a parallel stranded structure inhibits HIV‐1 integrase

Abstract
Integration of a DNA copy of the HIV‐1 genome into chromosomal DNA of infected cells is a key step of viral replication. Integration is carried out by integrase, a viral protein which binds to both ends of viral DNA and catalyses reactions of the 3′‐end processing and strand transfer. A 3′‐3′ branched oligonucleotide functionalised by the intercalator oxazolopyridocarbazole at each 5′‐end was found to inhibit integration in vitro. We show that both a specific (G,A) sequence and the OPC intercalating agent contribute to the capability of the branched oligonucleotide to form a parallel stranded structure responsible for the inhibition.