Characterization and lipid phase effect on the interaction of GBV-C E2-derived peptide, P6-2VIR576, with lipid membranes relating it with the HIV-1 FP inhibition

Abstract This study is an extension of our previous paper on the interaction of AcP6-2 and the VIR576 peptides with DPPC: DPPS (3:2) and DMPC: DMPS (3:2) model membranes [ Colloids and Surfaces A . 532 ( 2017 ) 483–492]. In the present contribution, the temperature effect and the role of the lipid phase in the lipid-peptide interaction were investigated. Moreover at the same time, relating them to HIV-1 FP inhibition. Several biophysics experiments as lipid-peptide binding, Trp fluorescence quenching and Atomic Force Microscopy (AFM) visualization were used to evidence the different interaction of the peptide depending on the physical state of the lipids. In addition, the inhibition effect of HIV-1 FP by P6-2 VIR576 peptide was conducted by fluorescence resonance energy transfer (FRET) and also by AFM microscopy. P6-2VIR576 showed a preference to the liquid crystalline phases from where the peptide can diffuse and interact with the gel phases. Firstly, P6-2VIR576 induces a rigidifying of the membrane to finally, promote the vanishing of these gel phases. Concerning to the inhibition of HIV-1 FP peptide by P6-2VIR576 peptide, FRET and AFM results evidencing P6-2VIR576 peptide is a promising structure to be in mind in the development of new or improved drugs in HIV therapies.