Characterization of a putative fusogenic sequence in the E2 hepatitis G virus protein.

With the aim of better understanding the fusion process mediated by the envelope proteins of the hepatitis G virus (HGV/GBV-C), we have investigated the interaction with model membranes of two overlapping peptides [(267-284) and (279-298)] belonging to the E2 structural protein. The peptides were compared for their ability to perturb lipid bilayers by means of different techniques such as differential scanning calorimetry and fluorescence spectroscopy. Furthermore, the conformational behaviour of the peptides in different membrane environments was studied by Fourier-transform infrared spectroscopy and circular dichroism.

Perturbations induced by synthetic peptides from hepatitis G virus structural proteins in lipid model membranes: a fluorescent approach.

The name HGV/GBV-C remains as an acronym for hepatitis G virus (HGV) and GB virus-C (GBV-C), strain variants of this enveloped RNA virus independently but simultaneously discovered in 1995. Nowadays there is no evidence that it causes hepatitis in humans either during initial infection or after long-term carriage, but it has been recently related with HIV regarding the inhibition of progression to AIDS. The overall genomic organization of HGV/GBV-C is similar to that of hepatitis C virus (HCV) and other members of the Flavivirus family in Hepacivirus genus.

Interaction of synthetic peptides corresponding to hepatitis G virus (HGV/GBV-C) E2 structural protein with phospholipid vesicles.

The interaction with phospholipid bilayers of two synthetic peptides with sequences corresponding to a segment next to the native N-terminus and an internal region of the E2 structural hepatitis G virus (HGV/GBV-C) protein [E2(7-26) and E2(279-298), respectively] has been characterized. Both peptides are water soluble but associate spontaneously with bilayers, showing higher affinity for anionic than zwitterionic membranes. However, whereas the E2(7-26) peptide is hardly transferred at all from water to the membrane interface, the E2(279-298) peptide is able to penetrate into negatively charged bilayers remaining close to the lipid/water interface.

Effects of overlapping GB virus C/hepatitis G virus synthetic peptides on biomembrane models.

The present study was undertaken to examine the physicochemical properties of three overlapping peptides belonging to the E2 envelope protein of Hepatitis G virus (GBV-C/HGV) and its interaction with phospholipid biomembrane models using biophysical techniques. We describe our findings concerning the surface activity and the interaction of the peptides with monolayers and liposomes composed of the zwitterionic phospholipids dipalmitoylphosphatidylcholine and dimyristoylphosphatidylcholine (DMPC) and a mixture of DMPC with the anionic phospholipid dimyristoylphosphatidylglycerol. The results inform about the effect of the chain length on their interaction with biomembrane models.

Interaction of three beta-interferon domains with liposomes and monolayers as model membranes.

The physicochemical properties of three peptides belonging to the beta-interferon (beta-IFN) molecule, -beta-IFN(13-20), beta-IFN(40-47) and beta-IFN(109-116)-, which have been described to be antigenic epitopes of the neutralising antibodies responsible of the failure of the Multiple Sclerosis therapy, and their palmitoylated derivatives were analysed. Peptides were synthesised by solid-phase methodologies and characterized by amino acid analysis, analytical high-performance liquid chromatography and electrospray mass spectrometry. The activity of free and derivatized peptides was determined.