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 bio-chemical 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 iden-tified several compounds specific for this protein-protein interaction. (Journal of Biomolecular Screening XXXX:xx-xx) Key words: HIV integrase, LEDGF/p75, protein-protein interaction, AlphaScreen, orthogonal mixture