A5036815532- Calcium Carbonate Crystallization and Inhibition
- Crystallization and Solubility Studies
- Lipid Membrane Structure and Behavior
- Cholesterol and Lipid Metabolism
- Paleontology and Stratigraphy of Fossils
- Atherosclerosis and Cardiovascular Diseases
- Metabolomics and Mass Spectrometry Studies
- Diatoms and Algae Research
- Computational Drug Discovery Methods
- Protein Structure and Dynamics
- Physiological and biochemical adaptations
- Marine Biology and Environmental Chemistry
- Advanced Electron Microscopy Techniques and Applications
- X-ray Diffraction in Crystallography
- Glycosylation and Glycoproteins Research
- Advanced X-ray Imaging Techniques
- Sphingolipid Metabolism and Signaling
- Lipoproteins and Cardiovascular Health
- Crystallography and molecular interactions
- Pickering emulsions and particle stabilization
- Advanced MRI Techniques and Applications
- Ichthyology and Marine Biology
- Drug Transport and Resistance Mechanisms
- Bone and Dental Protein Studies
- Fish Ecology and Management Studies
Weizmann Institute of Science
2015-2025
Ben-Gurion University of the Negev
2011
The formation of atherosclerotic plaques in the blood vessel walls is result LDL particle uptake, and consequently cholesterol accumulation macrophage cells. Excess eventually results crystal deposition, hallmark mature atheromas. We followed crystals J774A.1 cells with time, during particles, using a previously developed correlative cryosoft X-ray tomography (cryo-SXT) stochastic optical reconstruction microscopy (STORM) technique. show, initial stages, small quadrilateral plates associated...
Significance Organisms form mineralized skeletons, many of which are composed calcium salts. Marine organisms extract ions from sea water. One the main unresolved issues is how concentrate by more than three orders magnitude to achieve mineral deposition in their skeleton. Here we determine state each calcium-containing vesicles inside spicule-building cells urchin larvae. We show that within one cell there a wide range concentrations and states solution solid. hypothesize concentration...
A comparative study of two structural isomers highlights the advantages bifuran vs. bithiophene units in conjugated systems, such as higher fluorescence, solubility, and increased stability oxidized species. Importantly, we have found that small unit bestows longer oligofurans, should be considered rational design π-conjugated systems.
Atherosclerosis is the major precursor of cardiovascular disease. The formation cholesterol crystals in atherosclerotic plaques associated with onset acute pathology. induce physical injury plaque core, promoting cell apoptosis and triggering an increased inflammatory response. Herein we address question how crystal occurs atherosclerosis. We demonstrate that three-dimensional (3D) can undergo directed nucleation from bilayer membranes containing two-dimensional (2D) crystalline domains....
We have developed a high resolution correlative method involving cryo-soft X-ray tomography (cryo-SXT) and stochastic optical reconstruction microscopy (STORM), which provides information in three dimensions on large cellular volumes at 70 nm resolution. Cryo-SXT morphologically identified localized aggregations of carbon-rich materials. STORM specific markers the desired epitopes, enabling colocalization between objects, this case cholesterol crystals, environment. The samples were studied...
Abstract The silica cell wall of diatoms, a widespread group unicellular microalgae, is an exquisite example for the ability organisms to finely sculpt minerals under strict biological control. prevailing paradigm diatom silicification that this invariably intracellular process, occurring inside specialized deposition vesicles are responsible precipitation and morphogenesis. Here, we study formation long silicified extensions characterize many species. We use cryo-electron tomography image...
Mucus is made of enormous mucin glycoproteins that polymerize by disulfide crosslinking in the Golgi apparatus. QSOX1 a catalyst bond formation localized to Golgi. Both and mucins are highly expressed goblet cells mucosal tissues, leading hypothesis catalyzes disulfide-mediated polymerization. We found knockout mice lacking had impaired mucus barrier function due production defective mucus. However, an investigation on molecular level revealed normal polymerization related glycoproteins....
Organisms evolve mechanisms that regulate the properties of biogenic crystals to support a wide range functions, from vision and camouflage communication thermal regulation. Yet, mechanism underlying formation diverse intracellular remains enigmatic. Here we unravel biochemical control over crystal morphogenesis in zebrafish iridophores. We show chemical composition determines their shape, particularly through ratio between nucleobases guanine hypoxanthine. reveal these variations are...
Pigmentation plays a vital role in the survival of organisms, supporting functions such as camouflage, communication, and mate attraction. In vertebrates, these are mediated by specialized pigment cells known chromatophores which, uric acid crystal-forming leucophores remain least understood, with little about their molecular mechanisms. A key question cell biology is whether different crystal chemistries require distinct pathways, or similar cellular processes drive formation diverse...
Abstract Transient amorphous phases are known as functional precursors in the formation of crystalline materials, both vivo and vitro. A common route to regulate calcium carbonate (ACC) crystallization is via direct interactions with negatively charged macromolecules. However, a less explored phenomenon that can influence such systems electrostatically driven Ca‐macromolecule dense phases. In this study, it shown how condensates form liquid–liquid phase separation (LLPS) be used control...
Organic crystals, and in particular guanine are widely used by multicellular organisms for manipulating light producing structural colors. Many single celled eukaryotic also produce organic is the most abundant type produced. Their functions thought to be related fact that nitrogen rich. Here we studied a freshwater unicellular alga, Phacotus lenticularis , found when growth medium depleted phosphorus, alga stops reproducing produces intracellular birefringent particles inside vesicles....
We employed in a correlative manner an unconventional combination of methods, comprising cathodoluminescence, cryo–scanning electron microscopy (SEM), and cryo–focused ion beam (FIB)-SEM, to examine the volumes thousands cubed micrometers from rabbit atherosclerotic tissues, maintained close-to-native conditions, with resolution tens nanometers. Data three different intralesional regions, at media–lesion interface, core, toward lumen, were analyzed following segmentation volume or surface...
Significance Some organisms evolved an extraordinary ability to control the formation of inorganic crystals. This is usually attributed localization biomineralization processes specialized and controlled cellular environments. However, traditional techniques are incompatible with investigations precipitation reactions in vivo, structural determinants these remain elusive. Here, we use state-of-the-art cryoelectron tomography visualize nanometer-scale resolution calcite by microalgae. The...
Controlling the morphology of crystalline materials is challenging, as crystals have a strong tendency toward thermodynamically stable structures. Yet, organisms form with distinct morphologies, such plate-like guanine produced by many terrestrial and aquatic species for light manipulation. Regulation crystal morphogenesis was hypothesized to entail physical growth restriction surrounding membrane, combined fine-tuned interactions between organic molecules growing crystal. Using...
We revisit the important issues of polymorphism, structure, and nucleation cholesterol·H2O using first-principles calculations based on dispersion-augmented density functional theory. For lesser known monoclinic polymorph, we obtain a fully extended H-bonded network in structure akin to that hexagonal ice. show energy triclinic polymorphs is similar, strongly suggesting kinetic environmental effects play significant role determining polymorph nucleation. Furthermore, find evidence support...
Objective— Cells use various mechanisms to maintain cellular cholesterol homeostasis including efflux of from the plasma membrane acceptors such as HDLs (high-density lipoproteins). Little is known about transfer cells into extracellular matrix. Using a unique monoclonal antibody that detects ordered arrays (ie, micro[or nano]-domains), we previously identified particles containing these domains accumulate in matrix during enrichment human monocyte-derived macrophages and are found...
During breast cancer bone metastasis, tumor cells interact with microenvironment components including inorganic minerals. Bone mineralization is a dynamic process and varies spatiotemporally as function of cancer-promoting conditions such age diet. The functional relationship between skeletal dissemination mineralization, however, unclear. Standard histological analysis metastasis frequently relies on prior demineralization bone, while methods that maintain mineral are often harsh damage...
We previously reported that cholesterol-enriched macrophages excrete cholesterol into the extracellular matrix. A monoclonal antibody detects microdomains labels deposited particles. Macro-phage deposition of depends, in part, on ABCG1, and this can be mobilized by HDL components reverse transport process. The objective current study was to determine whether ABCA1 also contributes macrophage cholesterol. functioned deposition. liver X receptor agonist, TO901317 (TO9), an ABCA1-inducing...
Biogenic crystals present a variety of complex morphologies that form with exquisite fidelity. In the case intricate coccoliths, calcite produced by marine algae, only single set crystallographic facets is utilized. It unclear which growth process can merge this simple habit species-specific architectures. Here, suite state-of-the-art electron microscopies used to follow both trajectories ex situ, and cellular environment in species Emiliania huxleyi. shown crystal alternates between space...
Abstract Cholesterol crystallization from mixtures of unesterified cholesterol with phospholipids and esters is believed to be a key event in atherosclerosis progression. Not much understood, however, about the influence lipid environment on crystallization. Here we study monohydrate crystal formation mixed bilayers palmitoyl‐oleoyl‐phosphatidylcholine (POPC), dipalmitoyl‐phosphatidylcholine (DPPC) sphingomyelin. We show that disordered sphingomyelin stabilize plates triclinic polymorph,...
Multistep mineralization processes are pivotal in the fabrication of functional materials and often characterized by far from equilibrium conditions high supersaturation. Interestingly, such 'nonclassical' pathways widespread biological systems, even though concentrating molecules well beyond their saturation level is incompatible with cellular homeostasis. Here, we show how polymer phase separation can facilitate bioinspired silica formation passively inorganic building blocks within dense...
Cholesterol is an essential component of animal cell membranes because it influences and controls membrane fluidity. also responsible for the most frequent lethal pathologies in developed countries its intimate association with atherosclerotic plaques, rupture which may cause heart attacks or strokes. The question under conditions cholesterol activity manifests itself, whether physiology pathology. answer complex, there probably not one certain answer. This review article has foundations...
"Out-of-pocket" association of Ag(+) to the tetradentate defect site mono-vacant Keggin and Wells-Dawson polyoxometalate (POM) cluster-anions is used direct formation water-soluble AgCl nanocubes.