The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Tomasz Róg - One of the best experts on this subject based on the ideXlab platform.
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Complexity of seemingly Simple Lipid nanodiscs.
Biochimica et biophysica acta. Biomembranes, 2020Co-Authors: Piotr Stepien, Bozena Augustyn, Chetan Poojari, Wojciech Galan, Agnieszka Polit, Ilpo Vattulainen, Anna Wisnieska-becker, Tomasz RógAbstract:Lipid nanodiscs are macromolecular assemblies, where a scaffold protein is wrapped around a nanosized disc of a Lipid bilayer, thus protecting the hydrocarbon chains at the disc edges from unfavorable interactions with water. These nanostructures have numerous applications in, e.g., nanotechnology and pharmaceutics, and in investigations of membrane proteins. Here, we present results based on atomistic molecular dynamics simulations combined with electron paramagnetic spectroscopy measurements on the structure and dynamics of Lipids in single-component nanodiscs. Our data highlight the existence of three distinctly different Lipid fractions: central Lipids residing in the center of a nanodisc, boundary Lipids in direct contact with a scaffold protein, and intermediate Lipids between these two regions. The central Lipids are highly ordered and characterized by slow diffusion. In this part of the nanodisc, the membrane is the thickest and characterized by a gel-like or liquid-ordered phase, having features common to cholesterol-rich membranes. The boundary Lipids in direct contact with the scaffold protein turned out to be less ordered and characterized by faster diffusion, and they remained in the liquid-disordered phase even at temperatures that were somewhat below the main phase transition temperature (Tm). The enthalpies associated with the central-boundary and central-intermediate transitions were similar to those observed for Lipids going through the main phase transition. Overall, the study reveals Lipid nanodiscs to be characterized by a complex internal structure, which is expected to influence membrane proteins placed in nanodiscs.
Piotr Stepien - One of the best experts on this subject based on the ideXlab platform.
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Complexity of seemingly Simple Lipid nanodiscs.
Biochimica et biophysica acta. Biomembranes, 2020Co-Authors: Piotr Stepien, Bozena Augustyn, Chetan Poojari, Wojciech Galan, Agnieszka Polit, Ilpo Vattulainen, Anna Wisnieska-becker, Tomasz RógAbstract:Lipid nanodiscs are macromolecular assemblies, where a scaffold protein is wrapped around a nanosized disc of a Lipid bilayer, thus protecting the hydrocarbon chains at the disc edges from unfavorable interactions with water. These nanostructures have numerous applications in, e.g., nanotechnology and pharmaceutics, and in investigations of membrane proteins. Here, we present results based on atomistic molecular dynamics simulations combined with electron paramagnetic spectroscopy measurements on the structure and dynamics of Lipids in single-component nanodiscs. Our data highlight the existence of three distinctly different Lipid fractions: central Lipids residing in the center of a nanodisc, boundary Lipids in direct contact with a scaffold protein, and intermediate Lipids between these two regions. The central Lipids are highly ordered and characterized by slow diffusion. In this part of the nanodisc, the membrane is the thickest and characterized by a gel-like or liquid-ordered phase, having features common to cholesterol-rich membranes. The boundary Lipids in direct contact with the scaffold protein turned out to be less ordered and characterized by faster diffusion, and they remained in the liquid-disordered phase even at temperatures that were somewhat below the main phase transition temperature (Tm). The enthalpies associated with the central-boundary and central-intermediate transitions were similar to those observed for Lipids going through the main phase transition. Overall, the study reveals Lipid nanodiscs to be characterized by a complex internal structure, which is expected to influence membrane proteins placed in nanodiscs.
Theerapong Puangmali - One of the best experts on this subject based on the ideXlab platform.
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in silico study of gold nanoparticle uptake into a mammalian cell interplay of size shape surface charge and aggregation
Journal of Physical Chemistry C, 2019Co-Authors: Thodsaphon Lunnoo, Jirawat Assawakhajornsak, Theerapong PuangmaliAbstract:The study of interactions between Au nanostructures and living cells is a fundamental aspect that can be applied for promising applications in nanomedicine. In the present work, we performed coarse-grained molecular dynamics (MD) simulations to observe the internalization pathways of Au nanostructures (nanospheres, nanocages, nanorods, nanoplates, and nanohexapods) into an idealized mammalian plasma membrane at an unprecedented level of complexity. Compared with a Simple Lipid bilayer model consisting of two Lipid species, the different cellular uptake pathways of the gold nanoparticle (AuNP) were found. We highlight that the complexity of the Lipid bilayer models plays an important role in the uptake pathway of nanoparticles (NPs). The permeability of aggregated AuNPs was much less than the NP counterpart. Spherical AuNPs showed pronounced size and surface charge dependence in their translocation through the plasma membrane. The translocation rates of different Au nanostructures were also evaluated, and ...
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in silico study of gold nanoparticle uptake into a mammalian cell interplay of size shape surface charge and aggregation
The Journal of Physical Chemistry, 2019Co-Authors: Thodsaphon Lunnoo, Jirawat Assawakhajornsak, Theerapong PuangmaliAbstract:The study of interactions between Au nanostructures and living cells is a fundamental aspect that can be applied for promising applications in nanomedicine. In the present work, we performed coarse-grained molecular dynamics (MD) simulations to observe the internalization pathways of Au nanostructures (nanospheres, nanocages, nanorods, nanoplates, and nanohexapods) into an idealized mammalian plasma membrane at an unprecedented level of complexity. Compared with a Simple Lipid bilayer model consisting of two Lipid species, the different cellular uptake pathways of the gold nanoparticle (AuNP) were found. We highlight that the complexity of the Lipid bilayer models plays an important role in the uptake pathway of nanoparticles (NPs). The permeability of aggregated AuNPs was much less than the NP counterpart. Spherical AuNPs showed pronounced size and surface charge dependence in their translocation through the plasma membrane. The translocation rates of different Au nanostructures were also evaluated, and we found that the Au nanohexapod exhibited highest cellular uptake. Understanding the interrelationship between size, shape, surface charge, and aggregation of Au nanostructures provides a clear view on the design of Au nanostructures for developing new diagnostic strategies and drug delivery.
Robert L. Hamilton - One of the best experts on this subject based on the ideXlab platform.
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Changes in Lipid Structure Produced by Surfactant Proteins SP-A, SP-B, and SP-C
American journal of respiratory cell and molecular biology, 1991Co-Authors: Mary C. Williams, Samuel Hawgood, Robert L. HamiltonAbstract:Pulmonary surfactant phosphoLipids may assume several different structures including tubular myelin, unilamellar and multilamellar vesicles, and others. These populations of materials appear to have similar phosphoLipid compositions but may differ in their association with surfactant proteins SP-A, SP-B, or SP-C. We have used electron microscopy to determine the changes in structure of Simple Lipid mixtures (phosphatidylglycerol, dipalmitoylphosphatidylcholine) produced by adding one or combinations of the three proteins. Adding SP-A to Lipids generated multilamellar structures composed of membranes with fuzzy or particulate surfaces. In contrast, SP-B or SP-C generated discoidal particles and structures that appeared to be sheets of membrane formed by associated particles. Used together, SP-A and SP-B reorganized some of the Lipid into tubular myelin, a structure that was not observed in SP-A, SP-C recombinants. These observations confirm the in vitro formation of tubular myelin reported by others and su...
Anna Wisnieska-becker - One of the best experts on this subject based on the ideXlab platform.
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Complexity of seemingly Simple Lipid nanodiscs.
Biochimica et biophysica acta. Biomembranes, 2020Co-Authors: Piotr Stepien, Bozena Augustyn, Chetan Poojari, Wojciech Galan, Agnieszka Polit, Ilpo Vattulainen, Anna Wisnieska-becker, Tomasz RógAbstract:Lipid nanodiscs are macromolecular assemblies, where a scaffold protein is wrapped around a nanosized disc of a Lipid bilayer, thus protecting the hydrocarbon chains at the disc edges from unfavorable interactions with water. These nanostructures have numerous applications in, e.g., nanotechnology and pharmaceutics, and in investigations of membrane proteins. Here, we present results based on atomistic molecular dynamics simulations combined with electron paramagnetic spectroscopy measurements on the structure and dynamics of Lipids in single-component nanodiscs. Our data highlight the existence of three distinctly different Lipid fractions: central Lipids residing in the center of a nanodisc, boundary Lipids in direct contact with a scaffold protein, and intermediate Lipids between these two regions. The central Lipids are highly ordered and characterized by slow diffusion. In this part of the nanodisc, the membrane is the thickest and characterized by a gel-like or liquid-ordered phase, having features common to cholesterol-rich membranes. The boundary Lipids in direct contact with the scaffold protein turned out to be less ordered and characterized by faster diffusion, and they remained in the liquid-disordered phase even at temperatures that were somewhat below the main phase transition temperature (Tm). The enthalpies associated with the central-boundary and central-intermediate transitions were similar to those observed for Lipids going through the main phase transition. Overall, the study reveals Lipid nanodiscs to be characterized by a complex internal structure, which is expected to influence membrane proteins placed in nanodiscs.