Defining and characterizing the step in the HIV-1 viral life cycle affected by fullerene derivatives

Zachary Sean Martinez, University of Texas at El Paso


Fullerene derivatives, both C60 and C70, were synthesized and characterized to test their activity against HIV-1 infection. The derivatives tested have previously been reported to inhibit HIV-1 replication and/or in vitro activity of reverse transcriptase. It was found that viruses produced in the presence of low micromolar concentrations of most of these fullerene derivatives exhibit a reduction in viral infectivity greater than 99%. Quantification of virion-associated viral RNA and p24 indicates that RNA packaging and viral production were unremarkable in these viruses. These compounds did not affect infectivity of mature virions, indicating no effect on the early steps of the viral life cycle, thus suggesting an effect on viral maturation. Analysis of Gag processing confirmed this mechanism of action, which is independent of the activity of protease as demonstrated by an in vitro enzymatic assay. As a result, fullerene derivatives potently impair viral infectivity of viruses harboring mutant proteases that developed resistance to multiple protease inhibitors in patients. Pull-down experiments using magnetic bead-immobilized compounds demonstrated that some C70 fullerene derivatives strongly bind to the HIV capsid-spacer peptide 1 Gag proteolytic fragment, showing that this viral protein is the target. Comparison of the antiviral activity of fullerene derivatives to that of other small molecules and peptides that block maturation by binding to the HIV-1 capsid protein indicates that fullerene derivatives exhibit a new mechanism of action.

Subject Area

Molecular biology|Cellular biology|Virology

Recommended Citation

Martinez, Zachary Sean, "Defining and characterizing the step in the HIV-1 viral life cycle affected by fullerene derivatives" (2016). ETD Collection for University of Texas, El Paso. AAI10118164.