Breaking the Brownian barrier: models and manifestations of molecular diffusion in complex fluids.

Over a century ago, Einstein formulated a precise mathematical model for describing Brownian motion. While this model adequately explains the diffusion of micron-sized particles in fluids, its limitations become apparent when applied to molecular self-diffusion in fluids. The foundational principles of Gaussianity and Markovianity, central to the Brownian diffusion paradigm, are insufficient for describing molecular diffusion, particularly in complex fluids characterized by intricate intermolecular interactions and hindered relaxation processes.

Selective assembly and insertion of ubiquicidin antimicrobial peptide in lipid monolayers.

Antimicrobial-resistant bacteria pose a significant threat to humans, prompting extensive research into developing new antimicrobial peptides (AMPs). The biomembrane is the first barrier of a biological cell, hence, comprehending the interaction and self-assembly of AMPs in and around such membranes is of great importance. In the present study, several biophysical techniques have been applied to explore the self-assembly of ubiquicidin (29-41), an archetypical AMP, in and around the phospholipid monolayers formed at air-water interface.

A transition from enemies to allies: how viruses improve drought resilience in plants.

Global crop production is severely affected by environmental factors such as drought, salinity, cold, flood etc. Among these stresses, drought is one of the major abiotic stresses reducing crop productivity. It is expected that drought conditions will further increase because of the increasing global temperature.

Modulation of Phase Behavior and Microscopic Dynamics in Cationic Vesicles by 1-Decyl-3-methylimidazolium Bromide.

Synthetic cationic lipids have garnered significant attention as promising candidates for gene/DNA transfection in therapeutic applications. The phase behavior of the vesicles formed by these lipids is intriguing, revealing intricate connections to the structure and dynamics of the membrane. These phenomena emerge from the complex interplay between hydrophobic and electrostatic interactions of the lipids.

Aspirin-Induced Ordering and Faster Dynamics of a Cationic Bilayer for Drug Encapsulation.

The lipid dynamics and phase play decisive roles in drug encapsulation and delivery to the intracellular target. Thus, understanding the dynamic and structural alterations of membranes induced by drugs is essential for targeted delivery. To this end, united-atom molecular dynamics simulations of a model bilayer, dioctadecyldimethylammonium bromide (DODAB), are performed in the absence and presence of the usual nonsteroidal anti-inflammatory drug (NSAID), aspirin, at 298, 310, and 345 K.

Effects of ionic liquids on biomembranes: A review on recent biophysical studies.

Ionic liquids (ILs) have been emerged as a versatile class of compounds that can be easily tuned to achieve desirable properties for various applications. The ability of ILs to interact with biomembranes has attracted significant interest, as they have been shown to modulate membrane properties in ways that may have implications for various biological processes. This review provides an overview of recent studies that have investigated the interaction between ILs and biomembranes.

Cholesterol-Controlled Interaction of Ionic Liquids with Model Cellular Membranes.

While ionic liquids (ILs) are considered as prospective ingredients of new antimicrobial agents, it is important to understand the adverse effects of these molecules on human cells. Since cholesterol is the essential component of a human cell membrane, in the present study, the effect of an imidazolium-based IL has been investigated on the model membrane in the presence of cholesterol. The area per sphingomyelin lipid is found to reduce in the presence of the IL, which is quantified by the area-surface pressure isotherm of the lipid monolayer formed at the air-water interface.

How 1,-Bis(3-alkylimidazolium-1-yl) Alkane Interacts with the Phospholipid Membrane and Impacts the Toxicity of Dicationic Ionic Liquids.

Ionic liquids based on doubly charged cations, often termed dicationic ionic liquids (DILs), offer robust physicochemical properties and low toxicity than conventional monocationic ionic liquids. In this design-based study, we used solid-state NMR spectroscopy to provide the interaction mechanism of two DILs, 1,-bis(3-alkylimidazolium-1-yl) alkane dibromide ([C(CIM)]·2Br, = 1, 6), with 1-palmitoyl-2-oleoyl--glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl--glycero-3-phospho-(1'--glycerol) (POPG) phospholipid membranes, to explain the low toxicity of DILs toward HeLa, , , and cell lines. Dications with a short linker and long terminal chains cause substantial perturbation to the bilayer structure, making them more membrane permeabilizing, as shown by fluorescence-based dye leakage assays.

Curcumin Accelerates the Lateral Motion of DPPC Membranes.

Curcumin, the main ingredient in turmeric, has attracted attention due to its potential anti-inflammatory, anticancer, wound-healing, and antioxidant properties. Though curcumin efficacy is related to its interaction with biomembranes, there are few reports on the effects of curcumin on the lateral motion of lipids, a fundamental process in the cell membrane. Employing the quasielastic neutron scattering technique, we explore the effects of curcumin on the lateral diffusion of the dipalmotylphosphatidylcholine (DPPC) membrane.

1,3 Dialkylated Imidazolium Ionic Liquid Causes Interdigitated Domains in a Phospholipid Membrane.

Amphiphilic imidazolium-based ionic liquids (ILs) have proven their efficacy in altering the membrane integrity and dynamics. The present article investigates the phase-separated domains in a 1,2-dipalmitoyl--glycero-3-phosphocholine (DPPC) membrane induced by 1,3 dialkylated imidazolium IL. Isotherm measurements on DPPC monolayers formed at the air-water interface have shown a decrease in the mean molecular area with the addition of this IL.

CRISPR guides induce gene silencing in plants in the absence of Cas.

Background: RNA-targeting CRISPR-Cas can provide potential advantages over DNA editing, such as avoiding pleiotropic effects of genome editing, providing precise spatiotemporal regulation, and expanded function including antiviral immunity.

Results: Here, we report the use of CRISPR-Cas13 in plants to reduce both viral and endogenous RNA. Unexpectedly, we observe that crRNA designed to guide Cas13 could, in the absence of the Cas13 protein, cause substantial reduction in RNA levels as well.

Thermodynamics and structure of model bio-membrane of liver lipids in presence of imidazolium-based ionic liquids.

Ionic liquids (ILs) are the attractions of researchers today due to their vast area of potential applications. For biomedical uses, it becomes essential to understand their interactions with cellular membrane. Here, the membrane is mimicked with lipid bilayer and monolayer composed of liver lipids extract.

Enhanced Microscopic Dynamics of a Liver Lipid Membrane in the Presence of an Ionic Liquid.

Ionic liquids (ILs) are an important class of emerging compounds, owing to their widespread industrial applications in high-performance lubricants for food and cellulose processing, despite their toxicity to living organisms. It is believed that this toxicity is related to their actions on the cellular membrane. Hence, it is vital to understand the interaction of ILs with cell membranes.

Understanding the Structure and Dynamics of Complex Biomembrane Interactions by Neutron Scattering Techniques.

The membrane is one of the key structural materials of biology at the cellular level. Composed predominantly of a bilayer of lipids with embedded and bound proteins, it defines the boundaries of the cell and many organelles essential to life and therefore is involved in almost all biological processes. Membrane-specific interactions, such as drug binding to a membrane receptor or the interactions of an antimicrobial compound with the lipid matrix of a pathogen membrane, are of interest across the scientific disciplines.

CRISPR-Cas RNA Targeting Using Transient Cas13a Expression in Nicotiana benthamiana.

Application of the CRISPR-Cas prokaryotic immune system for single-stranded RNA targeting will have significant impacts on RNA analysis and engineering. The class 2 Type VI CRISPR-Cas13 system is an RNA-guided RNA-nuclease system capable of binding and cleaving target single-stranded RNA substrates in a sequence-specific manner. In addition to RNA interference, the Cas13a system has application from manipulating RNA modifications, to editing RNA sequence, to use as a nucleic acid detection tool.

Ubiquicidin-Derived Peptides Selectively Interact with the Anionic Phospholipid Membrane.

Ubiquicidin (UBI)/ribosomal protein S30 (RS30) is an intracellular protein with antimicrobial activities against various pathogens. UBI (29-41) and UBI (31-38) are two crucial peptides derived from Ubiquicidin, which have shown potential as infection imaging probes. Here, we report the interactions of UBI-derived peptides with anionic and zwitterionic phospholipid membranes.

Antimicrobial Peptides: Vestiges of Past or Modern Therapeutics?

The ubiquitous occurrence of Antimicrobial Peptides (AMPs) in all domains of life emphasizes their crucial role as ancient mediators of host defense. Despite their antiquity and prolonged history of exposure to pathogens, endogenous AMPs continue to serve as effective antibiotics. An "evolutionary arms race" between host and pathogen resulted in structural diversity of AMPs, leading these molecules to retain activity against a wide range of pathogens, including antibiotic-resistant microbes.

Imidazolium-based ionic liquids cause mammalian cell death due to modulated structures and dynamics of cellular membrane.

Here, we report the toxic effects of various imidazolium-based ionic liquids (ILs) with varying hydrocarbon chain lengths, on different human cell lines. Multiple biological assays have shown that the ILs with long hydrocarbon chains have stronger adverse effect especially on human liver cancer cells (Huh-7.5 cells).

Unraveling the Role of Monoolein in Fluidity and Dynamical Response of a Mixed Cationic Lipid Bilayer.

The maintenance of cell membrane fluidity is of critical importance for various cellular functions. At lower temperatures when membrane fluidity decreases, plants and cyanobacteria react by introducing unsaturation in the lipids, so that the membranes return to a more fluidic state. To probe how introduction of unsaturation leads to reduced membrane fluidity, a model cationic lipid dioctadecyldimethylammonium bromide (DODAB) has been chosen, and the effects of an unsaturated lipid monoolein (MO) on the structural dynamics and phase behavior of DODAB have been monitored by quasielastic neutron scattering and time-resolved fluorescence measurements.

Dynamic Landscape in Self-Assembled Surfactant Aggregates.

A process in which a disordered system of pre-existing molecules generates an organized structure through specific, local interactions among the molecules themselves is termed molecular self-assembly. Micelles, microemulsions, and vesicles are examples of such self-assembled systems where amphiphilic molecules are involved. As the functional properties of these systems (such as wetting and emulsification, release of solubilized drugs, etc.

Effect of an Antimicrobial Peptide on Lateral Segregation of Lipids: A Structure and Dynamics Study by Neutron Scattering.

Antimicrobial peptides are one of the most promising classes of antibiotic agents for drug-resistant bacteria. Although the mechanisms of their action are not fully understood, many of them are found to interact with the target bacterial membrane, causing different degrees of perturbations. In this work, we directly observed that a short peptide disturbs membranes by inducing lateral segregation of lipids without forming pores or destroying membranes.

Neutron Scattering Studies of the Interplay of Amyloid β Peptide(1-40) and An Anionic Lipid 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol.

The interaction between lipid bilayers and Amyloid β peptide (Aβ) plays a critical role in proliferation of Alzheimer's disease (AD). AD is expected to affect one in every 85 humans by 2050, and therefore, deciphering the interplay of Aβ and lipid bilayers at the molecular level is of profound importance. In this work, we applied an array of neutron scattering methods to study the structure and dynamics of Aβ(1-40) interacting 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) bilayers.