Membrane curvature is no longer thought of as a passive property of the membrane; rather, it is considered as an ac- tive, regulated state that serves various purposes in the cell such as between cells and organelle d...Membrane curvature is no longer thought of as a passive property of the membrane; rather, it is considered as an ac- tive, regulated state that serves various purposes in the cell such as between cells and organelle definition. While transport is usually mediated by tiny membrane bubbles known as vesicles or membrane tubules, such communication requires complex interplay between the lipid bilayers and cytosolic proteins such as members of the Bin/Amphiphysin/Rvs （BAR） superfam- ily of proteins. With rapid developments in novel experimental techniques, membrane remodeling has become a rapidly emerging new field in recent years. Molecular dynamics （MD） simulations are important tools for obtaining atomistic information regarding the structural and dynamic aspects of biological systems and for understanding the physics-related aspects. The availability of more sophisticated experimental data poses challenges to the theoretical community for devel- oping novel theoretical and computational techniques that can be used to better interpret the experimental results to obtain further functional insights. In this review, we summarize the general mechanisms underlying membrane remodeling con- trolled or mediated by proteins. While studies combining experiments and molecular dynamics simulations recall existing mechanistic models, concurrently, they extend the role of different BAR domain proteins during membrane remodeling pro- cesses. We review these recent findings, focusing on how multiscale molecular dynamics simulations aid in understanding the physical basis of BAR domain proteins, as a representative of membrane-remodeling proteins.展开更多
We investigate how an externally imposed curvature influences lipid segregation on two-phase-coexistent membranes. We show that the bending-modulus contrast of the two phases and the curvature act together to yield a ...We investigate how an externally imposed curvature influences lipid segregation on two-phase-coexistent membranes. We show that the bending-modulus contrast of the two phases and the curvature act together to yield a reduced effective line tension. On largely curved membranes, a state of multiple domains （or rafts） forms due to a mechanism analogous to that causing magnetic-vortex formation in type-II superconductors. We determine the criterion for such a multi-domain state to occur; we then calculate respectively the size of the domains formed on cylindrically and spherically curved membranes.展开更多
We propose a mathematically rigorous method to measure the spontaneous curvature of a bilayer membrane by molecular dynamics(MD)simulation,which provides description of the molecular mechanisms that cause the spontane...We propose a mathematically rigorous method to measure the spontaneous curvature of a bilayer membrane by molecular dynamics(MD)simulation,which provides description of the molecular mechanisms that cause the spontaneous curvature.As a main result,for the membrane setup investigated,the spontaneous curvature is proved to be a constant plus twice the mean curvature of the membrane in its tensionless ground state.The spontaneous curvature due to the built-in transbilayer asymmetry of the membrane in terms of lipid shape is studied by the proposed method.A linear dependence of the spontaneous curvature with respect to the head-bead diameter difference and the lipid mixing ratio is discovered.The consistency with the theoretical results provides evidence supporting the validity of our method.展开更多
Curvature is one of the most important features of lipid membranes in living cells,which significantly influences the structure of lipid membranes and their interaction with proteins.Taken the human islet amyloid poly...Curvature is one of the most important features of lipid membranes in living cells,which significantly influences the structure of lipid membranes and their interaction with proteins.Taken the human islet amyloid polypeptide(h IAPP),an important protein related to the pathogenesis of type II diabetes,as an example,we performed molecular dynamics(MD)simulations to study the interaction between the protein and the lipid structures with varied curvatures.We found that the lipids in the high curvature membrane pack loosely with high mobility.The h IAPP initially forms H-bonds with the membrane surface that anchored the protein,and then inserts into the membrane through the hydrophobic interactions between the residues and the hydrophobic tails of the lipids.h IAPP can insert into the membrane more deeply with a larger curvature and with a stronger binding strength.Our result provided important insights into the mechanism of the membrane curvature-dependent property of proteins with molecular details.展开更多
The membrane’s dynamics is very important for cells.A membrane in 2-dimensional space can be seen as an incompressible closed curve in a plane or a cylindrical surface in 3-dimensional space.In this paper,we design a...The membrane’s dynamics is very important for cells.A membrane in 2-dimensional space can be seen as an incompressible closed curve in a plane or a cylindrical surface in 3-dimensional space.In this paper,we design a second-order accurate numerical algorithm to simulate the shape transformation of the membrane.In the algorithm,we use the tangent angles to present the curve and avoid the difficulties from the constraint of curve’s incompressible condition.A lot of interesting phenomena are obtained.Some of them are very like the life processes of cells,such as exocytosis and endocytosis.Furthermore,we can see the relation between two dynamic models clearly.At last,considering the influence of the inner incompressible fluids partially,we add a constraint:the area circled by the membrane maintain invariable.The numerical results show the dynamic motions of a curve remaining its local arc length and inner area constant.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.21403182)the Research Grants Council of Hong Kong,China(Grant No.City U 21300014)
文摘Membrane curvature is no longer thought of as a passive property of the membrane; rather, it is considered as an ac- tive, regulated state that serves various purposes in the cell such as between cells and organelle definition. While transport is usually mediated by tiny membrane bubbles known as vesicles or membrane tubules, such communication requires complex interplay between the lipid bilayers and cytosolic proteins such as members of the Bin/Amphiphysin/Rvs （BAR） superfam- ily of proteins. With rapid developments in novel experimental techniques, membrane remodeling has become a rapidly emerging new field in recent years. Molecular dynamics （MD） simulations are important tools for obtaining atomistic information regarding the structural and dynamic aspects of biological systems and for understanding the physics-related aspects. The availability of more sophisticated experimental data poses challenges to the theoretical community for devel- oping novel theoretical and computational techniques that can be used to better interpret the experimental results to obtain further functional insights. In this review, we summarize the general mechanisms underlying membrane remodeling con- trolled or mediated by proteins. While studies combining experiments and molecular dynamics simulations recall existing mechanistic models, concurrently, they extend the role of different BAR domain proteins during membrane remodeling pro- cesses. We review these recent findings, focusing on how multiscale molecular dynamics simulations aid in understanding the physical basis of BAR domain proteins, as a representative of membrane-remodeling proteins.
基金Project supported by the Hundred-Talent Program of the Chinese Academy of Sciences(FY)the National Science Foundation of USA via Grant DMR-1106014(RLBS,JVS)
文摘We investigate how an externally imposed curvature influences lipid segregation on two-phase-coexistent membranes. We show that the bending-modulus contrast of the two phases and the curvature act together to yield a reduced effective line tension. On largely curved membranes, a state of multiple domains （or rafts） forms due to a mechanism analogous to that causing magnetic-vortex formation in type-II superconductors. We determine the criterion for such a multi-domain state to occur; we then calculate respectively the size of the domains formed on cylindrically and spherically curved membranes.
基金the financial support through the Natural Science Foundation of China No.11004131the financial support by the Natural Science Foundation of China No.50930003.
文摘We propose a mathematically rigorous method to measure the spontaneous curvature of a bilayer membrane by molecular dynamics(MD)simulation,which provides description of the molecular mechanisms that cause the spontaneous curvature.As a main result,for the membrane setup investigated,the spontaneous curvature is proved to be a constant plus twice the mean curvature of the membrane in its tensionless ground state.The spontaneous curvature due to the built-in transbilayer asymmetry of the membrane in terms of lipid shape is studied by the proposed method.A linear dependence of the spontaneous curvature with respect to the head-bead diameter difference and the lipid mixing ratio is discovered.The consistency with the theoretical results provides evidence supporting the validity of our method.
基金supported by funds from the National Natural Science Foundation of China(Grants 11932017,11772054,11772055,and 11532009)supported by the Fundamental Research Funds for the Central Universities(Grant 2019QNA4060)。
文摘Curvature is one of the most important features of lipid membranes in living cells,which significantly influences the structure of lipid membranes and their interaction with proteins.Taken the human islet amyloid polypeptide(h IAPP),an important protein related to the pathogenesis of type II diabetes,as an example,we performed molecular dynamics(MD)simulations to study the interaction between the protein and the lipid structures with varied curvatures.We found that the lipids in the high curvature membrane pack loosely with high mobility.The h IAPP initially forms H-bonds with the membrane surface that anchored the protein,and then inserts into the membrane through the hydrophobic interactions between the residues and the hydrophobic tails of the lipids.h IAPP can insert into the membrane more deeply with a larger curvature and with a stronger binding strength.Our result provided important insights into the mechanism of the membrane curvature-dependent property of proteins with molecular details.
基金the special funds for Major State Research Projects 2005CB321704National Science Foundation of China for Distinguished Young Scholars 10225103 and 20490222.
文摘The membrane’s dynamics is very important for cells.A membrane in 2-dimensional space can be seen as an incompressible closed curve in a plane or a cylindrical surface in 3-dimensional space.In this paper,we design a second-order accurate numerical algorithm to simulate the shape transformation of the membrane.In the algorithm,we use the tangent angles to present the curve and avoid the difficulties from the constraint of curve’s incompressible condition.A lot of interesting phenomena are obtained.Some of them are very like the life processes of cells,such as exocytosis and endocytosis.Furthermore,we can see the relation between two dynamic models clearly.At last,considering the influence of the inner incompressible fluids partially,we add a constraint:the area circled by the membrane maintain invariable.The numerical results show the dynamic motions of a curve remaining its local arc length and inner area constant.
