Bifunctional Chimera That Coordinately Targets Human Immunodeficiency Virus 1 Envelope Gp120 and the Host-Cell CCR5 Coreceptor at the Virus-Cell Interface

To address the urgent need for new agents to reduce the global occurrence and spread of AIDS, we investigated the underlying hypothesis that antagonists of the HIV-1 envelope (Env) gp120 protein and the host-cell coreceptor (CoR) protein can be covalently joined into bifunctional synergistic combinations with improved antiviral capabilities. A synthetic protocol was established to covalently combine a CCR5 small-molecule antagonist and a gp120 peptide triazole antagonist to form the bifunctional chimera. Importantly, the chimeric inhibitor preserved the specific targeting properties of the two separate chimera components and, at the same time, exhibited low to subnanomolar potencies in inhibiting cell infection by different pseudoviruses, which were substantially greater than those of a noncovalent mixture of the individual components. The results demonstrate that targeting the virus-cell interface with a single molecule can result in improved potencies and also the introduction of new phenotypes to the chimeric inhibitor, such as the irreversible inactivation of HIV-1.