Screening for antiviral inhibitors of the HIV integrase-LEDGF/p75 interaction using the AlphaScreen luminescent proximity assay

Small-molecule inhibitors of HIV integrase (HIV IN) have emerged as a promising new class of antivirals for the treatment of HIV/AIDS. The compounds currently approved or in clinical development specifically target HIV DNA integration and were identified using strand-transfer assays targeting the HIV IN/viral DNA complex. The authors have developed a second biochemical assay for identification of HIV integrase inhibitors, targeting the interaction between HIV IN and the cellular cofactor LEDGF/p75. They developed a luminescent proximity assay (AlphaScreen) designed to measure the association of the 80-amino-acid integrase binding domain of LEDGF/p75 with the 163-amino-acid catalytic core domain of HIV IN. This assay proved to be quite robust (with a Z' factor of 0.84 in screening libraries arrayed as orthogonal mixtures) and successfully identified several compounds specific for this protein-protein interaction.