Insight into the mechanism of action of EP-39, a bevirimat derivative that inhibits HIV-1 maturation

Aymeric Neyret (1) , Bernard Gay (1) , Anaïs Cransac (1) , Laurence Briant (1) , Pascale Coric (2) , Serge Turcaud (3) , Philippe Laugâa (2) , Serge Bouaziz (2, 4) , Nathalie Chazal (1)

1 IRIM - Institut de Recherche en Infectiologie de Montpellier
2 CiTCoM - UMR 8038 - Cibles Thérapeutiques et conception de médicaments
3 LCBPT - UMR 8601 - Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques
4 UPCG - UMR_S 640/UMR 8151 - Unité de Pharmacologie Chimique et Génétique

Maturation of human immunodeficiency virus type 1 (HIV-1) particles is a key step for viral infectivity. This process can be blocked using maturation inhibitors (MIs) that affect the cleavage of the capsid-spacer peptide 1 (CA-SP1) junction. Here, we investigated the mechanisms underlying the activity of EP-39, a bevirimat (BVM) derivative with better hydrosolubility. To this aim, we selected in vitro EP-39- and BVM-resistant mutants. We found that EP-39-resistant viruses have four mutations within the CA domain (CA-A194T, CA-T200N, CA-V230I, and CA-V230A) and one in the first residue of SP1 (SP1-A1V). We also identified six mutations that confer BVM resistance (CA-A194T, CA-L231F, CA-L231M, SP1-A1V, SP1-S5N and SP1-V7A). To characterize the EP-39 and BVM-resistant mutants, we studied EP-39 effects on mutant virus replication and performed a biochemical analysis with both MIs. We observed common and distinct characteristics, suggesting that, although EP-39 and BVM share the same chemical skeleton, they could interact in a different way with the Gag polyprotein precursor (Pr55Gag). Using an in silico approach, we observed that EP-39 and BVM present different predicted positions on the hexameric crystal structure of the CACTD-SP1 Gag fragment. To clearly understand the relationship between assembly and maturation, we investigated the impact of all identified mutations on virus assembly by expressing Pr55Gag mutants. Finally, using NMR, we have shown that the interaction of EP-39 with a peptide carrying the SP1-A1V mutation (CA-SP1(A1V)-NC) is almost suppressed in comparison with the wild type peptide. These results suggest that EP-39 and BVM could interact differently with the Pr55Gag lattice and that the mutation of the first SP1 residue induces a loss of interaction between Pr55Gag and EP-39.

Mots clés: NMRStructure; Docking; Pr55Gag; HIV-1; Maturation; Maturation inhibitors; Assembly

Domaines: Virologie

Aymeric Neyret, Bernard Gay, Anaïs Cransac, Laurence Briant, Pascale Coric, et al.. Insight into the mechanism of action of EP-39, a bevirimat derivative that inhibits HIV-1 maturation. Antiviral Research, 2019, 164, pp.162-175. ⟨10.1016/j.antiviral.2019.02.014⟩. ⟨hal-02147099⟩