Isolation and characterization of a small antiretroviral molecule affecting HIV-1 capsid morphology

BACKGROUND: Formation of an HIV-1 particle with a conical core structure is a prerequisite for the subsequent infectivity of the virus particle. We have previously described that glycineamide (G-NH(2)) when added to the culture medium of infected cells induces non-infectious HIV-1 particles with aberrant core structures. RESULTS: Here we demonstrate that it is not G-NH(2 )itself but a metabolite thereof that displays antiviral activity. We show that conversion of G-NH(2 )to its antiviral metabolite is catalyzed by an enzyme present in bovine and porcine but surprisingly not in human serum. Structure determination by NMR suggested that the active G-NH(2 )metabolite was α-hydroxy-glycineamide (α-HGA). Chemically synthesized α-HGA inhibited HIV-1 replication to the same degree as G-NH(2), unlike a number of other synthesized analogues of G-NH(2 )which had no effect on HIV-1 replication. Comparisons by capillary electrophoresis and HPLC of the metabolite with the chemically synthesized α-HGA further confirmed that the antiviral G-NH(2)-metabolite indeed was α-HGA. CONCLUSION: α-HGA has an unusually simple structure and a novel mechanism of antiviral action. Thus, α-HGA could be a lead for new antiviral substances belonging to a new class of anti-HIV drugs, i.e. capsid assembly inhibitors.