Article
Chemistry, Medicinal
Victor L. Cruz, Javier Ramos, Javier Martinez-Salazar, Manuel Montalban-Lopez, Mercedes Maqueda
Summary: The AS-48 bacteriocin is a potent antimicrobial polypeptide with enhanced stability due to its circular sequence of peptidic bonds. A computational study was conducted to analyze the membrane disruption mechanism, revealing the two-stage process of peptide binding and membrane poration. The detailed atomistic information obtained from the simulations can help in designing more potent antimicrobial therapies.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2021)
Article
Chemistry, Multidisciplinary
Hironori Sugiyama, Toshihisa Osaki, Shoji Takeuchi, Taro Toyota
Summary: Liposomes, molecular self-assemblies resembling biological membranes, are a promising scaffold for investigating the complexity of living cells. Exposed to steady flow conditions, liposomes were found to accumulate even macromolecules without pore formation, showing that external flow caused an asymmetry in the composition of anionic phospholipids between the inner and outer leaflets. This study opens new research interests in understanding the nature of biological membranes under steady flow conditions.
Article
Physics, Multidisciplinary
Brian Dincau, Emilie Dressaire, Alban Sauret
Summary: Whether it's pipes, highways, or arteries that are clogged, stopping the flow is always inconvenient and sometimes dangerous.
Article
Cell Biology
Fabio Lolicato, Roberto Saleppico, Alessandra Griffo, Annalena Meyer, Federica Scollo, Bianca Pokrandt, Hans-Michael Muller, Helge Ewers, Hendrik Hahl, Jean-Baptiste Fleury, Ralf Seemann, Martin Hof, Britta Brugger, Karin Jacobs, Ilpo Vattulainen, Walter Nickel
Summary: This study found that cholesterol can promote the recruitment and translocation of FGF2 in cells, as well as enhance its binding to PI(4,5)P2. Through molecular dynamics simulations and experiments, it was revealed that cholesterol modulates the binding of FGF2 to PI(4,5)P2 by increasing the visibility of PI(4,5)P2 on the membrane surface, inducing the clustering of PI(4,5)P2 molecules, and increasing membrane tension.
JOURNAL OF CELL BIOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Mehrnaz Mojtabavi, Sandra J. Greive, Alfred A. Antson, Meni Wanunu
Summary: The application of nanopores as label-free, single-molecule biosensors for structural features in biomolecules has been widely researched. While biological and solid-state nanopores have been extensively used, the study of hybrid nanopores, where an artificial membrane replaces the organic support membrane of proteins, is limited. In this study, a lipid-free hybrid nanopore was developed by connecting a solid-state pore and the G20c portal protein. The chemical functionalization of the synthetic nanopore improved the stability, lifetime, and voltage resilience of the hybrid pore. Additionally, electric-field-driven and motor protein-mediated transport of DNA molecules through the hybrid nanopore was demonstrated. This protein/solid-state device offers potential advantages in sensing and sequencing with higher resolution, signal-to-noise ratio, and throughput compared to conventional membrane-embedded protein platforms.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Xiaoyan Liu, Joakim Stenhammar, Hakan Wennerstrom, Emma Sparr
Summary: The bending energy of the lipid membrane plays a central role in biological processes involving vesicles. By studying the response of single-component giant unilamellar vesicles (GUVs) to external osmotic stress, it is found that the osmotic pressure is balanced by the free energy of membrane bending. After equilibration, the exchange of external glucose solution for pure water leads to rapid formation of monodisperse daughter vesicles inside the GUVs through an endocytosis-like process. The results indicate that the bending energies stored in GUVs are higher than previously thought and have potential consequences for vesicle fusion/fission and osmotic regulation in living cells.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Analytical
Essraa A. Hussein, Ryan J. White
Summary: Resistive pulse sensing using ion channel proteins has evolved as a single-molecule approach with high molecular selectivity, but requires a stable lipid membrane. The newly developed gold electrode-supported bilayer technology offers high spatial resolution but suffers from channel current decay. Introducing a silver nanoneedle to support lipid bilayer formation and ion channel measurements can mitigate current decay and produce stable DC channel currents.
ANALYTICAL CHEMISTRY
(2021)
Article
Biology
Jianping Li, Yang Shen, Yanke Chen, Zhengfeng Zhang, Shaojie Ma, Qianfen Wan, Qiong Tong, Clemens Glaubitz, Maili Liu, Jun Yang
Summary: The study presents a well-defined homo-trimeric structure of DgkA in phospholipid bilayers determined by solid-state NMR spectroscopy, providing insights into the influence of membrane mimetic environments on membrane proteins. Comparisons with structures solved by solution NMR and X-ray crystallography highlight differences in symmetry and dynamics, demonstrating the significance of membrane mimetic environments in shaping the structure and dynamics of membrane proteins.
COMMUNICATIONS BIOLOGY
(2021)
Article
Chemistry, Medicinal
Xu Ouyang, Beibei Li, Yinyin Yang, Zufang Ba, Jingying Zhang, Tianyue Zhang, Linlin Chang, Fangyan Zhang, Yun Zhang, Hui Liu, Sanhu Gou, Jingman Ni
Summary: This study presents a new approach to improve antimicrobial peptides by designing and synthesizing a series of analogues and screening out the most effective one, E11K4K10. E11K4K10 showed low induction of drug-resistant bacteria when used alone, and it could also inhibit the development of drug resistance when used in combination with traditional antibiotics. Furthermore, E11K4K10 demonstrated excellent therapeutic effects on a mouse model of pulmonary bacterial infection.
JOURNAL OF MEDICINAL CHEMISTRY
(2022)
Article
Computer Science, Artificial Intelligence
Dongdong Cheng, Qingsheng Zhu, Jinlong Huang, Quanwang Wu, Lijun Yang
Summary: The paper introduces a novel MST-based clustering algorithm LDP-MST, which utilizes local density peaks and a new distance measurement method to effectively discover clusters with complex structures. The experimental results demonstrate that the proposed algorithm is competitive with state-of-the-art methods in cluster discovery.
IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING
(2021)
Article
Chemistry, Physical
Yun-Chiao Yao, Zhongwu Li, Alice J. Gillen, Shari Yosinski, Mark A. Reed, Aleksandr Noy
Summary: Carbon nanotube porins demonstrate excellent biocompatibility and unique water and ion transport properties. Gating transport with external voltage increases control over ion flow and selectivity. The optimal gated CNTP device consists of a semiconducting CNTP inserted into a small membrane patch containing an internally conductive layer.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Jean-Baptiste Fleury, Marco Werner, Xavier Le Guevel, Vladimir A. Baulin
Summary: This study investigates how protein corona significantly alters the interaction mode between nanoparticles and lipid bilayers. In the presence of proteins, the length of spikes on the nanoparticle surface exposed to lipid bilayers can be effectively reduced, impacting the dynamics of pore formation. Protein corona is not only crucial for the interaction between NPs and membranes, but may also change their mode of interaction.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Chemistry, Physical
Oleg V. Kondrashov, Sergey A. Akimov
Summary: This study theoretically investigates the effects of solid support and lateral tension on membrane deformation, peptide adsorption, and interaction. The results suggest that under typical experimental conditions, the adsorption energy and surface concentration are affected and should be taken into account in experimental observations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Emad Pirhadi, Juan M. Vanegas, Mithila Farin, Jeffrey W. Schertzer, Xin Yong
Summary: Biological membranes are vital for the survival of living organisms, and molecular dynamics is an essential computational tool for studying them. However, the current methods of simulating biomembranes lack control over the lipid ratio and can influence research findings. This study investigates the role of membrane-building protocols and initial stress state on the interaction between small molecules and asymmetric membranes.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Biochemistry & Molecular Biology
Sarmini Nageswaran, Juliane Haipeter, Jonathan F. E. Bodenschatz, Ruth Meyer, Sarah Koester, Claudia Steinem
Summary: Within a cell, intermediate filaments play an important role in maintaining mechanical stability. However, little attention has been given to their interaction with the plasma membrane. In this study, we developed an in vitro model to investigate how intermediate filaments react to membrane stretching. We found that the filaments undergo reorganization and elongation in response to stretching, especially in a dense network.
Article
Biochemistry & Molecular Biology
Susanne Karsch, Fanny Buechau, Thomas M. Magin, Andreas Janshoff
CELLULAR AND MOLECULAR LIFE SCIENCES
(2020)
Article
Biophysics
Peter Muehlenbrock, Kira Herwig, Loan Vuong, Ingo Mey, Claudia Steinem
BIOPHYSICAL JOURNAL
(2020)
Review
Biophysics
Hannes Witt, Filip Savic, Sarah Verbeek, Jorn Dietz, Gesa Tarantola, Marieelen Oelkers, Burkhard Geil, Andreas Janshoff
Summary: Membrane-coated colloidal probes are a powerful model system that enables visualization of biological processes with minimal reliance on fluorescent labels. They have been widely used for studying membrane fusion processes and can provide detailed insights with high throughput.
EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS
(2021)
Article
Multidisciplinary Sciences
Anna Schepers, Charlotta Lorenz, Peter Nietmann, Andreas Janshoff, Stefan Klumpp, Sarah Koster
Summary: The mechanical properties of cells are largely determined by the cytoskeleton, with the intermediate filament network being the most extensible and stress-resilient. A multiscale approach is used to analyze the contributions of single-filament mechanics, filament length, and interactions between filaments to vimentin IF network mechanics. Hydrophobic contributions primarily affect filament elongation kinetics, while electrostatics influence filament-filament interactions.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Multidisciplinary
Mark Skamrahl, Hongtao Pang, Maximilian Ferle, Jannis Gottwald, Angela Ruebeling, Riccardo Maraspini, Alf Honigmann, Tabea A. Oswald, Andreas Janshoff
Summary: This study demonstrates the essential role of ZO proteins in efficient collective cell migration by maintaining tissue fluidity and controlling proliferation. Loss of ZO1 and ZO2 leads to actomyosin remodeling in individual cells, altering their viscoelastic properties and resulting in a tug-of-war between subpopulations with distinct morphological and mechanical properties. Co-cultures of wildtype and dKD cells migrate inefficiently due to differences in contractility rather than adhesion.
Article
Chemistry, Analytical
Gabriele Selvaggio, Robert Nissler, Peter Nietmann, Atanu Patra, Lukas J. Patalag, Andreas Janshoff, Daniel B. Werz, Sebastian Kruss
Summary: Near-infrared (NIR) fluorophores are advantageous in biophotonics for their reduced scattering, increased tissue penetration, and low phototoxicity. This study demonstrates the NIR fluorescence of two benzene-fused oligo-BODIPYs in their hexameric and octameric forms, with emission characteristics varying with solvent polarity.
Review
Biochemistry & Molecular Biology
Andreas Janshoff
Summary: Epithelial cells form tight barriers on the outer and inner surfaces of organs and cavities, facing diverse environmental challenges that rely on their dynamic viscoelastic properties. Studying mechanical properties through atomic force microscopy and viscoelastic models can provide insights into cell responses to external forces. The cortex plays a significant role in the response of cells to external forces, as discussed in recent deformation studies.
BIOCHEMICAL SOCIETY TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Joern Dietz, Marieelen Oelkers, Raphael Hubrich, Angel Perez-Lara, Reinhard Jahn, Claudia Steinem, Andreas Janshoff
Summary: A mechanism is proposed for full-length synaptotagmin-1 to interact with anionic bilayers and promote fusion in the presence of SNAREs. It is shown that the binding of synaptotagmin-1 to membranes depends on the presence and content of PI(4,5)P-2 in the absence of Ca2+. The interaction forces switch from weak to strong upon addition of Ca2+, leading to partial unfolding of the protein. Fusion of vesicles equipped with synaptotagmin-1 and synaptobrevin 2 with target membranes containing PS and PI(4,5)P-2 is accelerated in the presence of Ca2+, which is further enhanced by ATP.
Article
Biology
Jonathan F. E. Bodenschatz, Karim Ajmail, Mark Skamrahl, Marian Vache, Jannis Gottwald, Stefan Nehls, Andreas Janshoff
Summary: The viscoelastic properties of epithelial cells were studied using indentation-retraction/relaxation experiments. The cells become stiffer but still retain their fluidity when subjected to shape changes. Sacrificing excess surface area allows the cells to respond to mechanical challenges without losing their ability to flow.
COMMUNICATIONS BIOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Nils L. Liebe, Ingo Mey, Loan Vuong, Fadi Shikho, Burkhard Geil, Andreas Janshoff, Claudia Steinem
Summary: The creation of artificial lipid bilayers on planar supports allows for a controlled study of membrane-confined processes. In this study, actomyosin networks were bound to supported planar lipid bilayers doped with phosphatidylinositol-4,5-bisphosphate (PtdIns[4,5]P2) via the membrane-actin linker ezrin. By analyzing this membrane system using high-resolution fluorescence microscopy, the researchers were able to understand the connectivity and contractility of the actomyosin network. They found that the network's architecture and dynamics depend not only on the PtdIns[4,5]P2 concentration, but also on the presence of negatively charged phosphatidylserine (PS).
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Silan Toy, Joern Dietz, Peter Naumann, Janina Trothe, Franziska Thomas, Ulf Diederichsen, Claudia Steinem, Andreas Janshoff
Summary: Cell adhesion molecules, such as E-cadherin, play a crucial role in various biological processes. Researchers synthesized E-cadherin mimetic peptides and attached them to solid-supported membranes on colloidal probes to identify this molecule on cell surfaces. Two different functionalization strategies were established, and binding studies showed successful attachment of the peptides to the membrane surface. The presence of E-cadherin on living cells was confirmed using colloidal probes functionalized with HAV-peptides.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Oncology
Ludovico Mori, Martine Ben Amar
Summary: This study investigates the impact of phenotypical heterogeneity on tumor growth and therapies using the Cancer Stem Model. The results confirm the descriptive power of the model and highlight the importance of considering stochastic factors for a more accurate understanding of tumor evolution and therapy outcomes.
Article
Multidisciplinary Sciences
Peter Nietmann, Kevin Kaub, Andrejus Suchenko, Susanne Stenz, Claas Warnecke, Mohan K. Balasubramanian, Andreas Janshoff
Summary: This study investigates the implications of different actins expressed in epithelial cells for network mechanics and dynamics. The authors find that gamma-actin forms stiffer networks compared to beta-actin, attributed to selective interactions with Mg2+-ions. They also observe that beta-actin networks show more small contraction foci, while gamma-actin networks have fewer but larger foci, indicative of a stronger interaction with myosin motors.
NATURE COMMUNICATIONS
(2023)
Article
Biophysics
Andreas Janshoff
Summary: This study investigated the viscoelastic properties of basolateral membranes derived from polarized MDCK II epithelia and found that compared with cells probed at the apical side, the basolateral membranes are more fluid and stiffer, but still follow the same universal scaling law.
BIOPHYSICAL REPORTS
(2021)
Article
Physics, Multidisciplinary
Niloufar Abtahi, Lila Bouzar, Nadia Saidi-Amroun, Martin Michael Muller
