References of "Stroobant, V"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailDetermination Of The Minimal Fusion Peptide Of Hiv, Siv And Blv Fusion Glycoproteins
Lorin, A.; Charloteaux, Benoît ULg; Lins, Laurence ULg et al

in Peptides For Youth - the Proceedings of the 20th American Peptidesymposium (2009), 611

The entry of enveloped viruses into target cells requires the fusion between the viral envelope and the target cell membrane. In the case of many viruses like HIV, SIV and BLV, the fusion is mediated by ... [more ▼]

The entry of enveloped viruses into target cells requires the fusion between the viral envelope and the target cell membrane. In the case of many viruses like HIV, SIV and BLV, the fusion is mediated by class 1 fusion glycoproteins located on the viral envelope. These fusion glycoproteins contain a region at their N-terminal extremity called the “fusion peptide”, which interact with the target membrane. Many mutagenesis studies showed that this region is required for mediating membrane fusion [1]. Moreover, synthetic peptides corresponding to the fusion peptide of many glycoproteins induce membrane fusion in vitro. Despite the large number of studies on synthetic fusion peptides, the region necessary and sufficient to induce optimal membrane fusion is not known. To determine this minimal fusion peptide, we used the “tilted peptide” theory. According to this theory, a helical peptide inserting obliquely into membranes induces fusion [2]. Moreover, the more tilted the peptide is, the more important the fusion is. Then, we postulate that the minimal fusion peptide corresponds to the shortest helical fragment able to insert into the membrane with an angle close to 45°. This peptide was predicted using the IMPALA algorithm, which allow to predict peptide-membrane interactions [3]. Fusogenicity of this peptide was then assessed in liposome lipid-mixing and leakage assays and compared to the fusogenicity of smaller and longer peptides to check the validity of the prediction. This methodology was used to determine successfully the minimal fusion peptide of three viruses, HIV, SIV and BLV. [less ▲]

Detailed reference viewed: 13 (0 ULg)
Full Text
Peer Reviewed
See detailThe Minimal Fusion Peptide Of Simian Immunodeficiency Virus Corresponds To The 11 First Residues Of Gp32
Lorin, A.; Lins, Laurence ULg; Stroobant, V. et al

in Journal of Peptide Science (2008), 14(4), 423-8

We had previously predicted successfully the minimal fusion peptides (FPs) of the human immunodeficiency virus 1 (HIV-1) gp41 and the bovine leukemia virus (BLV) gp30 using an original approach based on ... [more ▼]

We had previously predicted successfully the minimal fusion peptides (FPs) of the human immunodeficiency virus 1 (HIV-1) gp41 and the bovine leukemia virus (BLV) gp30 using an original approach based on the obliquity/fusogenicity relationship of tilted peptides. In this paper, we have used the same method to predict the shortest FP capable of inducing optimal fusion in vitro of the simian immunodeficiency virus (SIV) mac isolate and of other SIVs and human immunodeficiency virus (HIV-2) isolates. In each case, the 11-residue-long peptide was predicted as the minimal FP. For the SIV mac isolate, liposome lipid-mixing and leakage assays confirmed that this peptide is the shortest peptide inducing optimal fusion in vitro, being therefore the minimal FP. These results are another piece of evidence that the tilted properties of FPs are important for the fusion process and that our method can be used to predict the minimal FPs of other viruses. [less ▲]

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailDetermination Of The Minimal Fusion Peptide Of Bovine Leukemia Virus Gp30
Lorin, A.; Lins, Laurence ULg; Stroobant, V. et al

in Biochemical and Biophysical Research Communications (2007), 355(3), 649-53

In this study, we determined the minimal N-terminal fusion peptide of the gp30 of the bovine leukemia virus on the basis of the tilted peptide theory. We first used molecular modelling to predict that the ... [more ▼]

In this study, we determined the minimal N-terminal fusion peptide of the gp30 of the bovine leukemia virus on the basis of the tilted peptide theory. We first used molecular modelling to predict that the gp30 minimal fusion peptide corresponds to the 15 first residues. Liposome lipid-mixing and leakage assays confirmed that the 15-residue long peptide induces fusion in vitro and that it is the shortest peptide inducing optimal fusion since longer peptides destabilize liposomes to the same extent but not shorter ones. The 15-residue long peptide can thus be considered as the minimal fusion peptide. The effect of mutations reported in the literature was also investigated. Interestingly, mutations related to glycoproteins unable to induce syncytia in cell-cell fusion assays correspond to peptides predicted as non-tilted. The relationship between obliquity and fusogenicity was also confirmed in vitro for one tilted and one non-tilted mutant peptide. [less ▲]

Detailed reference viewed: 1 (0 ULg)
Full Text
Peer Reviewed
See detailLipid-Destabilizing Properties Of The Hydrophobic Helices H8 And H9 From Colicin E1
Lins, Laurence ULg; El Kirat, K.; Charloteaux, Benoît ULg et al

in Molecular Membrane Biology (2007), 24(5-6), 419-30

Colicins are toxic proteins produced by Escherichia coli that must cross the membrane to exert their activity. The lipid insertion of their pf domain is linked to a conformational change which enables the ... [more ▼]

Colicins are toxic proteins produced by Escherichia coli that must cross the membrane to exert their activity. The lipid insertion of their pf domain is linked to a conformational change which enables the penetration of a hydrophobic hairpin. They provide useful models to more generally study insertion of proteins, channel formation and protein translocation in and across membranes. In this paper, we study the lipid-destabilizing properties of helices H8 and H9 forming the hydrophobic hairpin of colicin E1. Modelling analysis suggests that those fragments behave like tilted peptides. The latter are characterized by an asymmetric distribution of their hydrophobic residues when helical. They are able to interact with a hydrophobic/hydrophilic interface (such as a lipid membrane) and to destabilize the organized system into which they insert. Fluorescence techniques using labelled liposomes clearly show that H9, and H8 to a lesser extent, destabilize lipid particles, by inducing fusion and leakage. AFM assays clearly indicate that H8 and especially H9 induce membrane fragilization. Holes in the membrane are even observed in the presence of H9. This behaviour is close to what is seen with viral fusion peptides. Those results suggest that the peptides could be involved in the toroidal pore formation of colicin E1, notably by disturbing the lipids and facilitating the insertion of the other, more hydrophilic, helices that will form the pore. Since tilted, lipid-destabilizing fragments are also common to membrane proteins and to signal sequences, we suggest that tilted peptides should have an ubiquitous role in the mechanism of insertion of proteins into membranes. [less ▲]

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailLipid-Destabilising Properties Of A Peptide With Structural Plasticity
Lorin, A.; Thomas, Annick ULg; Stroobant, V. et al

in Chemistry and Physics of Lipids (2006), 141(1-2), 185-96

The Chameleon peptide (Cham) is a peptide designed from two regions of the GB1 protein, one folded as an alpha-helix and the other as a beta structure. Depending on the environment, the Cham peptide ... [more ▼]

The Chameleon peptide (Cham) is a peptide designed from two regions of the GB1 protein, one folded as an alpha-helix and the other as a beta structure. Depending on the environment, the Cham peptide adopts an alpha or a beta conformation when inserted in different locations of GB1. This environment dependence is also observed for tilted peptides. These short protein fragments, able to destabilise organised system, are mainly folded in beta structure in water and in alpha helix in a hydrophobic environment, like the lipid bilayer. In this paper, we tested whether the Cham peptide can be qualified as a tilted peptide. For this, we have compared the properties of Cham peptide (hydrophobicity, destabilising properties, conformation) to those of tilted peptides. The results suggest that Cham is a tilted peptide. Our study, together the presence of tilted fragments in transconformational proteins, suggests a relationship between tilted peptides and structural lability. [less ▲]

Detailed reference viewed: 11 (2 ULg)
Full Text
Peer Reviewed
See detailThe N-terminal 12 residue long peptide of HIV gp41 is the minimal peptide sufficient to induce significant T-cell-like membrane destabilization in vitro.
Charloteaux, Benoît ULg; Lorin, A.; Crowet, Jean-Marc ULg et al

in Journal of molecular biology (2006), 359(3), 597-609

Here, we predicted the minimal N-terminal fragment of gp41 required to induce significant membrane destabilization using IMPALA. This algorithm is dedicated to predict peptide interaction with a membrane ... [more ▼]

Here, we predicted the minimal N-terminal fragment of gp41 required to induce significant membrane destabilization using IMPALA. This algorithm is dedicated to predict peptide interaction with a membrane. We based our prediction of the minimal fusion peptide on the tilted peptide theory. This theory proposes that some protein fragments having a peculiar distribution of hydrophobicity adopt a tilted orientation at a hydrophobic/hydrophilic interface. As a result of this orientation, tilted peptides should disrupt the interface. We analysed in silico the membrane-interacting properties of gp41 N-terminal peptides of different length derived from the isolate BRU and from an alignment of 710 HIV strains available on the Los Alamos National Laboratory. Molecular modelling results indicated that the 12 residue long peptide should be the minimal fusion peptide. We then assayed lipid-mixing and leakage of T-cell-like liposomes with N-terminal peptides of different length as first challenge of our predictions. Experimental results confirmed that the 12 residue long peptide is necessary and sufficient to induce membrane destabilization to the same extent as the 23 residue long fusion peptide. In silico analysis of some fusion-incompetent mutants presented in the literature further revealed that they cannot insert into a modelled membrane correctly tilted. According to this work, the tilted peptide model appears to explain at least partly the membrane destabilization properties of HIV fusion peptide. [less ▲]

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailDistribution Of Hydrophobic Residues Is Crucial For The Fusogenic Properties Of The Ebola Virus Gp2 Fusion Peptide
Adam, B.; Lins, Laurence ULg; Stroobant, V. et al

in Journal of Virology (2004), 78(4), 2131-6

The lipid-destabilizing properties of the N-terminal domain of the GP2 of Ebola virus were investigated. Our results suggest that the domain of Ebola virus needed for fusion is shorter than that ... [more ▼]

The lipid-destabilizing properties of the N-terminal domain of the GP2 of Ebola virus were investigated. Our results suggest that the domain of Ebola virus needed for fusion is shorter than that previously reported. The fusogenic properties of this domain are related to its oblique orientation at the lipid/water interface owing to an asymmetric distribution of the hydrophobic residues when helical. [less ▲]

Detailed reference viewed: 5 (0 ULg)