Dataset Information

Two adjacent domains (141-150 and 151-160) of apoE covalently linked to a class A amphipathic helical peptide exhibit opposite atherogenic effects.

ABSTRACT: We recently described anti-atherogenic properties of the dual domain peptide Ac-hE18A-NH(2) derived by covalently linking the heparin binding domain 141-150 of apoE to 18A, a class A amphipathic helical peptide. In this paper we have compared the properties of Ac-hE18A-NH(2) with the non-heparin binding 151-160 region of apoE linked to 18A (Ac-nhE18A-NH(2)).Both peptides were highly helical in solution and in association with lipids. Ac-hE18A-NH(2) and not Ac-nhE18A-NH(2) enhanced uptake of low density lipoprotein (LDL) in HepG2 cells. While Ac-hE18A-NH(2) retarded the electrophoretic mobility of LDL, Ac-nhE18A-NH(2) slightly enhanced mobility. Ac-hE18A-NH(2) reduced monocyte association with endothelial cells, while Ac-nhE18A-NH(2) increased it. Ac-hE18A-NH(2) also reduced lipid hydroperoxide content of LDL while Ac-nhE18A-NH(2) increased it. A single administration of Ac-hE18A-NH(2) (100 ?g/mouse) into apoE null mice dramatically reduced cholesterol (from 600 mg/dL to 180 mg/dL at 5 min and to 60 mg/dL at 5h) while Ac-nhE18A-NH(2) had no effect. Administration (100 ?g/mouse/day, three days a week) into apoE null mice for six weeks showed Ac-hE18A-NH(2) group having a moderate aortic sinus lesion reduction compared with the control group (-15.1%), while the Ac-nhE18A-NH(2) administered group had increased lesion area (+33.0% vs controls and 36.1% vs Ac-hE18A-NH(2)). Plasma from mice administered Ac-hE18A-NH(2) for six weeks showed a significant reduction in plasma cholesterol and triglyceride levels and increase in paraoxonase-1 (PON-1) activity compared to controls, while Ac-nhE18A-NH(2) caused no change in plasma cholesterol and decreased PON-1 activity.It is proposed that Ac-hE18A-NH(2) reduced lesion progression in apoE null mice due to its anti-inflammatory and lipoprotein clearing properties, while Ac-nhE18A-NH(2) exhibited pro-atherogenic effects.

SUBMITTER: Nayyar G

PROVIDER: S-EPMC2997865 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Two adjacent domains (141-150 and 151-160) of apoE covalently linked to a class A amphipathic helical peptide exhibit opposite atherogenic effects.

Nayyar Gaurav G Handattu Shaila P SP Monroe Candyce E CE Chaddha Manjula M Datta Geeta G Mishra Vinod K VK Keenum Tamara D TD Palgunachari Mayakonda N MN Garber David W DW Anantharamaiah G M GM

Atherosclerosis 20101027 2

<h4>Objective</h4>We recently described anti-atherogenic properties of the dual domain peptide Ac-hE18A-NH(2) derived by covalently linking the heparin binding domain 141-150 of apoE to 18A, a class A amphipathic helical peptide. In this paper we have compared the properties of Ac-hE18A-NH(2) with the non-heparin binding 151-160 region of apoE linked to 18A (Ac-nhE18A-NH(2)).<h4>Methods and results</h4>Both peptides were highly helical in solution and in association with lipids. Ac-hE18A-NH(2) a ...[more]

PMID: 21030022

Similar Datasets

Project description:HP (2-20) is a 19-aa, amphipathic, ?-helical peptide with antimicrobial properties that was derived from the N-terminus of Helicobacter pylori ribosomal protein L1. We previously showed that increasing the net hydrophobicity of HP (2-20) by substituting Trp for Gln(17) and Asp(19) (Anal 3) increased the peptide's antimicrobial activity. In hydrophobic medium, Anal 3 forms an amphipathic structure consisting of an N-terminal random coil region (residues 2-5) and an extended helical region (residues 6-20). To investigate the structure-activity relationship of Anal 3, we substituted Pro for Glu(9) (Anal 3-Pro) and then examined the new peptide's three-dimensional structure, antimicrobial activity and mechanism of action. Anal 3-Pro had an ?-helical structure in the presence of trifluoroethanol (TFE) and sodium dodecyl sulfate (SDS). NMR spectroscopic analysis of Anal 3-Pro's tertiary structure in SDS micelles confirmed that the kink potential introduced by Pro(10) was responsible for the helix distortion. We also found that Anal 3-Pro exhibited about 4 times greater antimicrobial activity than Anal 3. Fluorescence activated flow cytometry and confocal fluorescence microscopy showed that incorporating a Pro-hinge into Anal 3 markedly reduced its membrane permeability so that it accumulated in the cytoplasm without remaining in the cell membrane. To investigate the translocation mechanism, we assessed its ability to release of FITC-dextran. The result showed Anal 3-Pro created a pore <1.8 nm in diameter, which is similar to buforin II. Notably, scanning electron microscopic observation of Candida albicans revealed that Anal 3-Pro and buforin II exert similar effects on cell membranes, whereas magainin 2 exerts a different, more damaging, effect. In addition, Anal 3-Pro assumed a helix-hinge-helix structure in the presence of biological membranes and formed micropores in both bacterial and fungal membranes, through which it entered the cytoplasm and tightly bound to DNA. These results indicate that the bending region of Anal 3- Pro peptide is prerequisite for effective antibiotic activity and may facilitate easy penetration of the lipid bilayers of the cell membrane.

Project description:L4F, an alpha helical peptide inspired by the lipid-binding domain of the ApoA1 protein, has potential applications in the reduction of inflammation involved with cardiovascular disease as well as an antioxidant effect that inhibits liver fibrosis. In addition to its biological activity, amphipathic peptides such as L4F are likely candidates to direct the molecular assembly of peptide nanostructures. Here we describe the stabilization of the amphipathic L4F peptide through fusion to a high molecular weight protein polymer. Comprised of multiple pentameric repeats, elastin-like polypeptides (ELPs) are biodegradable protein polymers inspired from the human gene for tropoelastin. Dynamic light scattering confirmed that the fusion peptide forms nanoparticles with a hydrodynamic radius of approximately 50nm, which is unexpectedly above that observed for the free ELP (~5.1nm). To further investigate their morphology, conventional and cryogenic transmission electron microscopy were used to reveal that they are unilamellar vesicles. On average, these vesicles are 49nm in radius with lamellae 8nm in thickness. To evaluate their therapeutic potential, the L4F nanoparticles were incubated with hepatic stellate cells. Stellate cell activation leads to hepatic fibrosis; furthermore, their activation is suppressed by anti-oxidant activity of ApoA1 mimetic peptides. Consistent with this observation, L4F nanoparticles were found to suppress hepatic stellate cell activation in vitro. To evaluate the in vivo potential for these nanostructures, their plasma pharmacokinetics were evaluated in rats. Despite the assembly of nanostructures, both free L4F and L4F nanoparticles exhibited similar half-lives of approximately 1h in plasma. This is the first study reporting the stabilization of peptide-based vesicles using ApoA1 mimetic peptides fused to a protein polymer; furthermore, this platform for peptide-vesicle assembly may have utility in the design of biodegradable nanostructures.

Dataset Information

Two adjacent domains (141-150 and 151-160) of apoE covalently linked to a class A amphipathic helical peptide exhibit opposite atherogenic effects.

Publications

Two adjacent domains (141-150 and 151-160) of apoE covalently linked to a class A amphipathic helical peptide exhibit opposite atherogenic effects.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets