Influence of the Saturation Chain and Head Group Charge of Phospholipids in the Interaction of Hepatitis G Virus Synthetic Peptides

Abstract

Using the Langmuir technique, we have studied the properties at the air/water interface and the interaction of the hepatitis G virus synthetic peptide E1(53-66) and its palmitoyl derivative with membrane phospholipids. These phospholipids had different characteristics referring to the net charge and saturation of the acyl chain. The palmitoyl derivative was more stable at the air/water interface and in the kinetic at constant area measurements showed higher incorporation to the monolayer. The interaction was higher for saturated phospholipids and those with a negative net charge. When the peptides were in the subphase, they produced changes in the miscibility of mixed monolayers composed of DPPC/DPPG or DOPC/DOPG. It can be deduced from the results obtained that electrostatic interactions play a major role, but when the peptide is derivatized with the palmitoyl chain, hydrophobic interactions are added to the former ones. The interaction is also influenced by the saturation of the acyl chain.

Interaction of GB Virus C/Hepatitis G Virus Synthetic Peptides with Lipid Langmuir Monolayers and Large Unilamellar Vesicles

“…Figure 1A shows the π-A compression isotherms of pure monolayers of the peptide E1(53-66) and DPPC and mixed films of mole fraction (X DPPC ) 0.2, 0.4, 0.6, and 0.8. The isotherms recorded for pure components, i.e., E1(53-66) 21 and DPPC, are in good agreement with the data already published. When the amount of E1(53-66) increases in the monolayer, different changes can be observed: (i) the DPPC phase transition disappears for monolayers of X DPPC ) 0.8, and (ii) the collapse pressure is only reached in the DPPC-E1(53-66) (0.8:0.2) mixture and its value is similar to the pure DPPC monolayer.…”

“…The syntheses of peptides E1(53-66) and PalmE1(53-66) have been previously described. 21 Briefly, peptides were synthesized manually by solid-phase Fmoc (N-R-fluorenylmethyloxycarbonyl) chemistry. They were synthesized on a Rink-amide resin with Fmocprotected amino acids.…”

Behaviour of a peptide sequence from the GB virus C/hepatitis G virus E2 protein in Langmuir monolayers: Its interaction with phospholipid membrane models

“…In order to determine the ability of these lipid monolayers to host the selected peptide sequence, we have studied the behaviour of pure and mixed peptide-lipid monolayers spread at the air-water interface, by analyzing and recording the π-A isotherms. Furthermore, Brewster angle microscopy (BAM), which is extensively used in studying the interactions between peptides and lipids at the interface [29,30], has provided complementary information about the morphology of the monolayers.…”

A study of HIV-1 FP inhibition by GBV-C peptides using lipid nano-assemblies

“…Surface behaviour at the air-water interface [15][16][17], and in peptide-lipid binding assays [11,18,19], leakage assays, fluorescence anisotropy or fluorescence resonance energy transfer studies [20,21] have each been applied to find a correlate between the capacity to inhibit HIV-1 FP in vitro and in vivo during cell-cell fusion inhibition studies [10,15]. In addition, topographical characterisation of model membranes showing the changes caused by HIV-1 FP or GBV-C peptides in various mixtures have been obtained by fluorescence microscopy (FM) and atomic force microscopy (AFM) [22,23].…”