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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Jing, Xiaona, et al.
(författare)
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Membrane adsorption and binding, cellular uptake and cytotoxicity of cell-penetrating peptidomimetics with alpha-peptide/beta-peptoid backbone : Effects of hydrogen bonding and alpha-chirality in the beta-peptoid residues
- 2012
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Ingår i: Biochimica et Biophysica Acta - Biomembranes. - : Elsevier BV. - 0005-2736 .- 1879-2642. ; 1818:11, s. 2660-2668
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Tidskriftsartikel (refereegranskat)abstract
- Cell-penetrating peptides (CPPs) provide a promising approach for enhancing intracellular delivery of therapeutic biomacromolecules by increasing transport through membrane barriers. Here, proteolytically stable cell-penetrating peptidomimetics with alpha-peptide/beta-peptoid backbone were studied to evaluate the effect of alpha-chirality in the beta-peptoid residues and the presence of guanidinium groups in the alpha-amino acid residues on membrane interaction. The molecular properties of the peptidomimetics in solution (surface and intramolecular hydrogen bonding, aqueous diffusion rate and molecular size) were studied along with their adsorption to lipid bilayers, cellular uptake, and toxicity. The surface hydrogen bonding ability of the peptidomimetics reflected their adsorbed amounts onto lipid bilayers as well as with their cellular uptake, indicating the importance of hydrogen bonding for their membrane interaction and cellular uptake. Ellipsometry studies further demonstrated that the presence of chiral centers in the beta-peptoid residues promotes a higher adsorption to anionic lipid bilayers, whereas circular dichroism results showed that alpha-chirality influences their overall mean residue ellipticity. The presence of guanidinium groups and alpha-chiral beta-peptoid residues was also found to have a significant positive effect on uptake in living cells. Together, the findings provide an improved understanding on the behavior of cell-penetrating peptidomimetics in the presence of lipid bilayers and live cells.
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| 3. |
- Yang, Mingjun, et al.
(författare)
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Delineating the conformational flexibility of trisaccharides from NMR spectroscopy experiments and computer simulations
- 2016
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 18:28, s. 18776-18794
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Tidskriftsartikel (refereegranskat)abstract
- The conformation of saccharides in solution is challenging to characterize in the context of a single well-defined three-dimensional structure. Instead, they are better represented by an ensemble of conformations associated with their structural diversity and flexibility. In this study, we delineate the conformational heterogeneity of five trisaccharides via a combination of experimental and computational techniques. Experimental NMR measurements target conformationally sensitive parameters, including J couplings and effective distances around the glycosidic linkages, while the computational simulations apply the well-calibrated additive CHARMM carbohydrate force field in combination with efficient enhanced sampling molecular dynamics simulation methods. Analysis of conformational heterogeneity is performed based on sampling of discreet states as defined by dihedral angles, on root-mean-square differences of Cartesian coordinates and on the extent of volume sampled. Conformational clustering, based on the glycosidic linkage dihedral angles, shows that accounting for the full range of sampled conformations is required to reproduce the experimental data, emphasizing the utility of the molecular simulations in obtaining an atomic detailed description of the conformational properties of the saccharides. Results show the presence of differential conformational preferences as a function of primary sequence and glycosidic linkage types. Significant differences in conformational ensembles associated with the anomeric configuration of a single glycosidic linkage reinforce the impact of such changes on the conformational properties of carbohydrates. The present structural insights of the studied trisaccharides represent a foundation for understanding the range of conformations adopted in larger oligosaccharides and how these molecules encode their conformational heterogeneity into the monosaccharide sequence.
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