An assay for real-time label-free monitoring of the integrase (IN) activity based on surface plasmon resonance was developed. This assay enabled direct monitoring of the integration of a viral doubled-stranded DNA into the host genome.
The strand transfer reaction was detected by using two different DNA targets: supercoiled plasmid (pUC 19) and short palindrome oligonucleotide. The effect of the length of the DNA target on the possibility to monitor the actual process of the strand transfer reaction is discussed.
The assay developed can serve as an important analytical tool to search for potential strand transfer reaction inhibitors as well as for the study of compounds interfering with the binding of ds long terminal repeats-IN complexes with the host DNA.