Peptide Assembly on the Membrane Determines the HIV-1 Inhibitory Activity of Dual-Targeting Fusion Inhibitor Peptides

Maria J Gomara,Isabel Haro,Yolanda Perez,Ramon Barnadas-Rodriguez,Hagen Von Briesen,Andreas Meyerhans,Anke Schultz,Alex Peralvarez-Marin,Javier P Martinez

doi:10.1038/s41598-019-40125-4

Abstract

Novel strategies in the design of HIV-1 fusion/entry inhibitors are based on the construction of dual-targeting fusion proteins and peptides with synergistic antiviral effects. In this work we describe the design of dual-targeting peptides composed of peptide domains of E2 and E1 envelope proteins from Human Pegivirus with the aim of targeting both the loop region and the fusion peptide domains of HIV-1 gp41. In a previous work, we described the inhibitory role of a highly conserved fragment of the E1 protein (domain 139–156) which interacts with the HIV-1 fusion peptide at the membrane level. Here, two different dual-targeting peptides, where this E1 peptide is located on the N- or the C-terminus respectively, have been chemically synthesized and their antiviral activities have been evaluated with HIV pseudotyped viruses from different clades. The study of the functional behaviour of peptides in a membranous environment attending to the peptide recognition of the target sites on gp41, the peptide conformation as well as the peptide affinity to the membrane, demonstrate that antiviral activity of the dual-targeting peptides is directly related to the peptide affinity and its subsequent assembly into the model membrane. The overall results point out to the necessity that fusion inhibitor peptides that specifically interfere with the N-terminal region of gp41 are embedded within the membrane in order to properly interact with their viral target.

Highlights

Sequential nature of the HIV-1 virus-cell fusion process characterized by the appearance of multiple targets that are susceptible to inhibition
DT-peptides composed of two different sequences from E1 and E2 glycoproteins of the non-pathogenic Human Pegivirus (HPgV) have been synthesized with the purpose of targeting two different regions of HIV-1 gp[41]: the loop and the fusion peptide (FP) (Fig. 1)
We have selected the (139–156) region of the E1 protein since recent structural studies carried out by our group have demonstrated the interaction of this peptide sequence with the HIV-1 FP at the membrane level interfering with the stabilization of the six-helix bundle formation in a membranous environment[19]

Summary

Introduction

Sequential nature of the HIV-1 virus-cell fusion process characterized by the appearance of multiple targets that are susceptible to inhibition. In this work the E2 sequence has been combined with an 18-mer domain from the E1 protein that interacts with the gp[41] fusion peptide at the membrane level and has a broad spectrum activity against HIV-1, as we previously reported[11]. Since HIV-1 gp[41] glycoprotein is confined between the cellular and the viral membranes, the study of the physicochemical processes involved at this interface is essential to understand the mode of action of fusion inhibitor peptides[12,13,14] As it has been previously reported, the interaction of fusion inhibitor peptides with biological membranes may be related to their inhibition efficiency[15,16,17]. In this work conformational and biophysical assays using model membranes have been carried out in order to understand better the requirements of DT-peptides for maintaining their functional behaviour as HIV-1 fusion inhibitors

Methods

Results

Conclusion