Time-dependent diaryl ether inhibitors of InhA: structure-activity relationship studies of enzyme inhibition, antibacterial activity, and in vivo efficacy.

The diaryl ethers are a novel class of antituberculosis drug candidates that inhibit InhA, the enoyl-ACP reductase involved in the fatty acid biosynthesis (FASII) pathway, and have antibacterial activity against both drug-sensitive and drug-resistant strains of Mycobacterium tuberculosis. In the present work, we demonstrate that two time-dependent B-ring modified diaryl ether InhA inhibitors have antibacterial activity in a mouse model of TB infection when delivered by intraperitoneal injection. We propose that the efficacy of these compounds is related to their residence time on the enzyme, and to identify structural features that modulate drug-target residence time in this system, we have explored the inhibition of InhA by a series of B-ring modified analogues.

Probing HIV-1 integrase inhibitor binding sites with position-specific integrase-DNA cross-linking assays.

HIV-1 integrase binds site-specifically to the ends of the viral cDNA. We used two HIV-1 integrase-DNA cross-linking assays to probe the binding sites of integrase inhibitors from different chemical families and with different strand transfer selectivities. The disulfide assay probes cross-linking between the integrase residue 148 and the 5'-terminal cytosine of the viral cDNA, and the Schiff base assay probes cross-linking between an integrase lysine residue and an abasic site placed at selected positions in the viral cDNA.

Effect of DNA modifications on DNA processing by HIV-1 integrase and inhibitor binding: role of DNA backbone flexibility and an open catalytic site.

Integration of the viral cDNA into host chromosomes is required for viral replication. Human immunodeficiency virus integrase catalyzes two sequential reactions, 3'-processing (3'-P) and strand transfer (ST). The first integrase inhibitors are undergoing clinical trial, but interactions of inhibitors with integrase and DNA are not well understood in the absence of a co-crystal structure.

Identification of an inhibitor-binding site to HIV-1 integrase with affinity acetylation and mass spectrometry.

We report a methodology that combines affinity acetylation with MS analysis for accurate mapping of an inhibitor-binding site to a target protein. For this purpose, we used a known HIV-1 integrase inhibitor containing aryl di-O-acetyl groups (Acetylated-Inhibitor). In addition, we designed a control compound (Acetylated-Control) that also contained an aryl di-O-acetyl group but did not inhibit HIV-1 integrase.