Article
Chemistry, Multidisciplinary
Sevde Puza, Stefanie Caesar, Chetan Poojari, Michael Jung, Ralf Seemann, Jochen S. Hub, Bianca Schrul, Jean-Baptiste Fleury
Summary: Lipid droplets (LDs) are organelles derived from the endoplasmic reticulum (ER) membrane and play a crucial role in lipid storage. The distribution of proteins between phospholipid bilayer and LD monolayer membranes is determined by the collective properties of protein-intrinsic and lipid-mediated features. In this study, researchers produced a freestanding phospholipid bilayer using microfluidics and observed the insertion of micrometer-sized LDs into the bilayer. They found that the LDs presented a lens shape and there was a diffusion barrier between the LD monolayer and the bilayer. This barrier may influence the partitioning of proteins between the ER membrane and LDs in living cells.
Review
Pharmacology & Pharmacy
Jennifer Christina Hartel, Nadine Merz, Sabine Groesch
Summary: The concept of proper resolution of inflammation has gained attention in recent years. This review focuses on the role of T cells and sphingolipids in the resolution of inflammation, providing insights into potential therapeutic approaches.
FRONTIERS IN PHARMACOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Gabriele C. Sosso, Prerna Sudera, Anna T. Backes, Thomas F. Whale, Janine Froehlich-Nowoisky, Mischa Bonn, Angelos Michaelides, Ellen H. G. Backus
Summary: By conducting experiments and simulations, this study systematically investigates the ice-nucleating ability of cholesterol in both crystalline and disordered self-assembled monolayers. A sweet spot in terms of the surface coverage of the monolayers is identified, where cholesterol enhances the structural order of interfacial water molecules and maximizes its ability to nucleate ice.
Article
Food Science & Technology
Natalia Kuzmina, Pavel Volynsky, Ivan Boldyrev, Anna Alekseeva
Summary: Bee venom PLA2 exhibits two additional interface binding modes and enzyme activity through constant switching between different orientations. This switching has biological significance in terms of enzyme movement along the membrane, product release in a biological milieu, and enzyme desorption from the bilayer surface.
Review
Biochemistry & Molecular Biology
Vanessa Judith Flegler, Tim Rasmussen, Bettina Boettcher
Summary: The ability to cope with and adapt to changes in the environment is essential for all organisms. This review discusses the current structural and functional models for the mechanically stimulated channel MscS, as well as the influence of certain membrane characteristics on gating.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Biophysics
Kayla Sapp, Alexander J. Sodt
Summary: Membrane shape transitions, such as fusion and fission, are crucial in biological processes. Understanding the mechanisms of curvature generation, including the effect of steric pressure from crowded proteins, is essential. The previously understood model is split into two parts: the reduction in steric pressure due to reduced collisions between proteins and the increased area available to individual proteins. The revised theory suggests that a purely entropic crowding mechanism cannot explain observations of reshaping at lower surface coverage, implying the presence of additional mechanisms.
BIOPHYSICAL JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Francesco Spinozzi, Jean-Pierre Alcaraz, Maria Grazia Ortore, Landry Gayet, Aurel Radulescu, Donald K. Martin, Marco Maccarini
Summary: This study provides a detailed characterization of liposomes containing OprF using small-angle neutron scattering (SANS) and a specific model for data analysis. The quantification of crucial structural information is important for the design and therapeutic applications of liposomal delivery systems.
Article
Chemistry, Multidisciplinary
Shixin Li, Fang Huang, Tie Xia, Yan Shi, Tongtao Yue
Summary: Phosphatidylinositol 4,5-bisphosphate (PIP2) is a critical molecule located at the inner leaflet of cell membrane, having anchoring and signaling functions. The interaction between PIP2 and the outer lipid domain is influenced by the length of sphingomyelin (SM) acyl chains, leading to either accumulation or expulsion of PIP2. These findings provide molecular insights into the regulatory mechanism of cell signal transduction.
Article
Biochemical Research Methods
Martin Kern, Sabrina Jaeger-Honz, Falk Schreiber, Bjorn Sommer
Summary: Molecular dynamics simulations provide insights into complex processes in cell membranes, and APL@Voro is a software that allows for interactive visualization and analysis of these simulations. It offers newly implemented algorithms and features to explore cell membrane compositions and dynamics.
Article
Biophysics
Victoria T. Reichelderfer, Andres F. Chaparro Sosa, Joel L. Kaar, Daniel K. Schwartz
Summary: The interactions between lipid bilayers and insulin can either stabilize or destabilize the protein, preventing or exacerbating the formation of amyloid fibrils.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2022)
Article
Biophysics
Nina Hartrampf, Samuel M. Leitao, Nils Winter, Henry Toombs-Ruane, James A. Frank, Petra Schwille, Dirk Trauner, Henri G. Franquelim
Summary: Sphingolipids are a diverse class of lipids found in the eukaryotic cell membrane. By using light-induced trans-cis isomerization of acyl chains, we developed a set of photoswitchable sphingolipids that can shuttle between liquid-ordered and liquid-disordered regions of model membranes. We investigated how these active sphingolipids remodel supported bilayers upon photoisomerization and found that certain lipids promote a reduction in liquid-ordered domain area while others induce an increase. These changes were reversible upon light-triggered isomerization, indicating the role of interfacial interactions in the formation of stable liquid-ordered domains.
BIOPHYSICAL JOURNAL
(2023)
Review
Microbiology
Marisela Velez
Summary: FtsZ, a cytoskeletal protein, plays a critical role in organizing the formation of the septal ring and coordinating bacterial cell division. Its association with the cell membrane is essential for its function. This review discusses how this association can affect the structure and dynamics of filaments and suggests that FtsZ's dynamics could also influence the underlying lipid membrane. This new insight could help understand how FtsZ assembly coordinates the positioning and recruitment of proteins in the septal ring with the activity of peptidoglycan synthesis machinery in the periplasmic space.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Chemistry, Physical
Majid Jafari, Faramarz Mehrnejad, Reza Talandashti, Farahnoosh Doustdar, Mohammad Reza Vakili, Afsaneh Lavasanifar
Summary: This study simulated 15 molecular systems to characterize the interactions between PAMAM dendrimers and membranes with different cholesterol ratios, explaining the structural features and geometry of their activity against cancer cells. The results demonstrated that cholesterol content in the membranes influenced the local membrane order parameters, and the dendrimers were able to create holes in cholesterol-containing membranes through hydrogen bonds and electrostatic interactions. Additionally, negatively charged phospholipids in cancer cell membranes played a crucial role in binding with the dendrimers, providing mechanistic insight into their activity against cancer cells.
APPLIED SURFACE SCIENCE
(2021)
Review
Biochemistry & Molecular Biology
Longteng Tang, Chong Fang
Summary: This review summarizes the progress in utilizing various ultrafast spectroscopies and time-resolved crystallography to study the on/off photoswitching pathways of reversibly switchable fluorescent proteins (RSFPs). While significant insights have been gained for some well-studied proteins, the real-time action details regarding the bidirectional cis-trans isomerization, proton transfer, and intermediate states remain unclear for most systems.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Navleen Kaur, Markus Fischer, Prashant Hitaishi, Sandeep Kumar, Veerendra Kumar Sharma, Sajal Kumar Ghosh, Gagandeep Kaur Gahlay, Holger A. Scheidt, Venus Singh Mithu
Summary: Dicationic ionic liquids (DILs) offer low toxicity and permeability to cell membranes, making them a promising option for harnessing biological activity.
Article
Multidisciplinary Sciences
Orawan Jakdetchai, Peter Eberhardt, Marvin Asido, Jagdeep Kaur, Clara Nassrin Kriebel, Jiafei Mao, Alexander J. Leeder, Lynda J. Brown, Richard C. D. Brown, Johanna Becker-Baldus, Christian Bamann, Josef Wachtveitl, Clemens Glaubitz
Summary: This study on the functional mechanism of the light-driven sodium pump KR2 uses solid-state nuclear magnetic resonance spectroscopy to reveal the interconversion of photointermediates and the perturbation caused by the nearby bound sodium ion. The findings suggest a mechanism different from traditional principles, highlighting the importance of understanding the role of sodium ion in retinal conformation changes.
Article
Chemistry, Multidisciplinary
Johanna Becker-Baldus, Alexander Leeder, Lynda J. Brown, Richard C. D. Brown, Christian Bamann, Clemens Glaubitz
Summary: Channelrhodopsin-2 (ChR2) is a light-gated cation channel used in optogenetics research. Despite the dark state structure being determined, the mechanistic understanding of channel function remains incomplete, requiring more detailed information on different photointermediates to be collected.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Nisha Chander, Johannes Morstein, Jan S. Bolten, Andrej Shemet, Pieter R. Cullis, Dirk Trauner, Dominik Witzigmann
Summary: Incorporation of photoswitchable-phosphatidylcholine analogs in conventional lipid nanoparticles can generate photoactivatable LNPs, allowing light-induced drug release at specific sites, which shows promising potential for clinical development.
Article
Chemistry, Multidisciplinary
Reika Tei, Johannes Morstein, Andrej Shemet, Dirk Trauner, Jeremy M. Baskin
Summary: Phosphatidic acids are important signaling molecules that regulate cell growth and proliferation through different pathways. Developing photoswitchable analogues of PA enables optical control of mTOR and Hippo signaling for potential applications in dissecting the effects of physiological and pathological PA signaling.
ACS CENTRAL SCIENCE
(2021)
Article
Biochemistry & Molecular Biology
Johannes Morstein, Taysir Bader, Ariana L. Cardillo, Julian Schackmann, Sudhat Ashok, James L. Hougland, Christine A. Hrycyna, Dirk H. Trauner, Mark D. Distefano
Summary: This study describes the development of photoswitchable analogs of an isoprenoid lipid and evaluates their potential for optically controlling the isoprenylation processing pathway. The results show that the analog effectively controls substrate prenylation but has minimal impact on subsequent processing steps.
ACS CHEMICAL BIOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Ziyang Zhang, Johannes Morstein, Andrew K. Ecker, Keelan Z. Guiley, Kevan M. Shokat
Summary: The study identified covalent chemical ligands for the common oncogenic mutant K-Ras(G12R), which bind in the Switch II pocket and irreversibly react with the mutant arginine residue. The X-ray crystal structure revealed a condensation product formed between the ligand and arginine 12's nitrogen atoms.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Johannes Morstein, Alice Capecchi, Konstantin Hinnah, ByungUk Park, Jerome Petit-Jacques, Reid C. Van Lehn, Jean-Louis Reymond, Dirk Trauner
Summary: Most bioactive molecules need to cross or be distributed into biological membranes, and natural products often have lipid modifications to facilitate molecule-membrane interactions. Lipidated natural products primarily contain saturated medium-chain lipids, and lipid conjugation can significantly modulate the permeability, cellular retention, subcellular localization, and bioactivity of small molecules.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Stefanie D. Pritzl, Johannes Morstein, Sophia Kahler, David B. Konrad, Dirk Trauner, Theobald Lohmuller
Summary: This study reports the optical control of lipid vesicles through vesicle fusion. It is observed that charge-mediated fusion enhances overall fusion performance and doping efficiency. Additionally, the use of phosphatidylcholine analogs with photo-switches affects the shape and properties of the resulting vesicles.
Article
Biophysics
Clara Nassrin Kriebel, Marvin Asido, Jagdeep Kaur, Jennifer Orth, Philipp Braun, Johanna Becker-Baldus, Josef Wachtveitl, Clemens Glaubitz
Summary: This study presents an extensive chemical shift resonance assignment of Krokinobacter eikastus rhodopsin 2 (KR2) within lipid bilayers using solid-state NMR spectroscopy. The H180A mutation was found to silence the response of KR2 to oxidized sodium, while proton pumping was observed in the absence of sodium. The study reveals specific long-range effects of the mutation along the sodium transfer pathway.
BIOPHYSICAL JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Tongil Ko, Mauricio M. Oliveira, Jessica M. Alapin, Johannes Morstein, Eric Klann, Dirk Trauner
Summary: Translation can be optically controlled using a photoswitchable version of puromycin, termed puroswitch. Puroswitch inhibits translation similarly to puromycin and can be used for tracking newly synthesized proteins in defined locations and at precise time points, making it a valuable biochemical tool.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Biochemistry & Molecular Biology
Johannes Morstein, Rebika Shrestha, Que N. Van, Cesar A. Lopez, Neha Arora, Marco Tonelli, Hong Liang, De Chen, Yong Zhou, John F. Hancock, Andrew G. Stephen, Thomas J. Turbyville, Kevan M. Shokat
Summary: Protein-membrane interactions (PMIs) play a crucial role in cellular signaling. By conjugating a medium-chain lipid tail to the covalent K-Ras(G12C) binder MRTX849, PMIs can be directly modulated. This strategy allows for selective modulation of transient PMIs.
ACS CHEMICAL BIOLOGY
(2023)
Article
Chemistry, Physical
Jinhuan Zhang, Clara Nassrin Kriebel, Zheng Wan, Man Shi, Clemens Glaubitz, Xiao He
Summary: In this study, an accurate and cost-effective method was developed to calculate the chemical shifts of membrane proteins. It was found that considering environmental factors can improve the accuracy of the predicted chemical shifts. Furthermore, the proposed method outperformed most empirical models in predicting the chemical shifts of key ligands and non-standard residues.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)