Dataset Information

Peptide-Mediated Liposome Fusion: The Effect of Anchor Positioning.

ABSTRACT: A minimal model system for membrane fusion, comprising two complementary peptides dubbed "E" and "K" joined to a cholesterol anchor via a polyethyleneglycol spacer, has previously been developed in our group. This system promotes the fusion of large unilamellar vesicles and facilitates liposome-cell fusion both in vitro and in vivo. Whilst several aspects of the system have previously been investigated to provide an insight as to how fusion is facilitated, anchor positioning has not yet been considered. In this study, the effects of placing the anchor at either the N-terminus or in the center of the peptide are investigated using a combination of circular dichroism spectroscopy, dynamic light scattering, and fluorescence assays. It was discovered that anchoring the "K" peptide in the center of the sequence had no effect on its structure, its ability to interact with membranes, or its ability to promote fusion, whereas anchoring the 'E' peptide in the middle of the sequence dramatically decreases fusion efficiency. We postulate that anchoring the 'E' peptide in the middle of the sequence disrupts its ability to form homodimers with peptides on the same membrane, leading to aggregation and content leakage.

SUBMITTER: Crone NSA

PROVIDER: S-EPMC5796160 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Peptide-Mediated Liposome Fusion: The Effect of Anchor Positioning.

Crone Niek S A NSA Minnee Dirk D Kros Alexander A Boyle Aimee L AL

International journal of molecular sciences 20180110 1

A minimal model system for membrane fusion, comprising two complementary peptides dubbed "E" and "K" joined to a cholesterol anchor via a polyethyleneglycol spacer, has previously been developed in our group. This system promotes the fusion of large unilamellar vesicles and facilitates liposome-cell fusion both in vitro and in vivo. Whilst several aspects of the system have previously been investigated to provide an insight as to how fusion is facilitated, anchor positioning has not yet been con ...[more]

PMID: 29320427

Similar Datasets

Project description:20 (enfuvirtide) and other peptides derived from the human immunodeficiency virus type 1 (HIV-1) gp41 C-terminal heptad repeat (CHR) region inhibit HIV fusion by binding to the hydrophobic grooves on the N-terminal heptad repeat (NHR) trimer and blocking six-helix-bundle (6-HB) formation. Several strategies focusing on the binding grooves of the NHR trimer have been adopted to increase the antiviral activity of the CHR peptides. Here, we developed a novel and simple strategy to greatly enhance the potency of the existing peptide-based HIV fusion inhibitors. First, we identified a shallow pocket adjacent to the groove in the N-terminal region of NHR trimer as a new drug target, and then we designed several short artificial peptides to fit this target. After the addition of IDL (Ile-Asp-Leu) to the C terminus of CHR peptide WQ or MT-WQ, the conjugated peptides, WQ-IDL and MT-WQ-IDL, showed much more potent activities than WQ and T20, respectively, in inhibiting HIV-1 IIIB infection. WQ-IDL and MT-WQ-IDL were also more effective than WQ in blocking HIV-1 Env-mediated membrane fusion and had higher levels of binding affinity with NHR peptide N46. We solved the crystal structure of the 6-HB formed by MT-WQ-IDL and N46 and found that, besides the N-terminal MT hook tail, the IDL tail anchor of MT-WQ-IDL also binds with the shallow hydrophobic pocket outside the groove of the NHR trimer, resulting in enhanced inhibition of HIV-1 fusion with the target cell. It is expected that this novel approach can be widely used to improve the potency of peptidic fusion inhibitors against other enveloped viruses with class I fusion proteins. IMPORTANCE:The hydrophobic groove of the human immunodeficiency virus type 1 (HIV-1) gp41 NHR trimer has been known as the classic drug target to develop fusion inhibitors derived from the gp41 CHR. Here, we developed a novel and simple strategy to improve the existing peptide-based HIV fusion inhibitors. We identified a shallow pocket adjacent to the groove in the NHR trimer and added a short artificial peptide consisting of three amino acids (IDL) to the C terminus of a fusion inhibitor to fit this new target. The inhibition activity of this new conjugated peptide was significantly enhanced, by 77-fold, making it much more potent than T20 (enfuvirtide) and suggesting that the IDL tail can be adopted for optimizing existing HIV-1 CHR peptide fusion inhibitors. This new approach of identifying a potential binding pocket outside the traditional target and creating an artificial tail anchor can be widely applied to design novel fusion inhibitors against other class I enveloped viruses, such as Middle East respiratory syndrome coronavirus (MERS-CoV).

Project description:While the importance of viral fusion peptides (e.g., hemagglutinin (HA) and gp41) in virus-cell membrane fusion is established, it is unclear how these peptides enhance membrane fusion, especially at low peptide/lipid ratios for which the peptides are not lytic. We assayed wild-type HA fusion peptide and two mutants, G1E and G13L, for their effects on the bilayer structure of 1,2-dioleoyl-3-sn-phosphatidylcholine/1,2-dioleoyl-3-sn-phosphatidylethanolamine/Sphingomyelin/Cholesterol (35:30:15:20) membranes, their structures in the lipid bilayer, and their effects on membrane fusion. All peptides bound to highly curved vesicles, but fusion was triggered only in the presence of poly(ethylene glycol). At low (1:200) peptide/lipid ratios, wild-type peptide enhanced remarkably the extent of content mixing and leakage along with the rate constants for these processes, and significantly enhanced the bilayer interior packing and filled the membrane free volume. The mutants caused no change in contents mixing or interior packing. Circular dichroism, polarized-attenuated total-internal-reflection Fourier-transform infrared spectroscopy measurements, and membrane perturbation measurements all conform to the inverted-V model for the structure of wild-type HA peptide. Similar measurements suggest that the G13L mutant adopts a less helical conformation in which the N-terminus moves closer to the bilayer interface, thus disrupting the V-structure. The G1E peptide barely perturbs the bilayer and may locate slightly above the interface. Fusion measurements suggest that the wild-type peptide promotes conversion of the stalk to an expanded trans-membrane contact intermediate through its ability to occupy hydrophobic space in a trans-membrane contact structure. While wild-type peptide increases the rate of initial intermediate and final pore formation, our results do not speak to the mechanisms for these effects, but they do leave open the possibility that it stabilizes the transition states for these events.

Dataset Information

Peptide-Mediated Liposome Fusion: The Effect of Anchor Positioning.

Publications

Peptide-Mediated Liposome Fusion: The Effect of Anchor Positioning.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure