A5027410618- Lipid Membrane Structure and Behavior
- Spectroscopy and Quantum Chemical Studies
- Nanopore and Nanochannel Transport Studies
- Protein Structure and Dynamics
- Force Microscopy Techniques and Applications
- Origins and Evolution of Life
- GaN-based semiconductor devices and materials
- Sphingolipid Metabolism and Signaling
- Cellular transport and secretion
- Surfactants and Colloidal Systems
- Ovarian function and disorders
- RNA and protein synthesis mechanisms
- Photosynthetic Processes and Mechanisms
- thermodynamics and calorimetric analyses
- Assisted Reproductive Technology and Twin Pregnancy
- Reproductive Biology and Fertility
- Semiconductor Quantum Structures and Devices
- Microbial Metabolic Engineering and Bioproduction
- Cinema and Media Studies
- RNA Interference and Gene Delivery
- Reproductive Health and Technologies
- Erythrocyte Function and Pathophysiology
- Advanced Thermodynamics and Statistical Mechanics
- Methane Hydrates and Related Phenomena
- Fungal and yeast genetics research
University of Washington
2015-2024
Cleveland Clinic
2023-2024
Cleveland Clinic Lerner College of Medicine
2023
Case Western Reserve University
2023
Washington University in St. Louis
2001-2022
Seattle University
2015-2021
University of Idaho
2021
Universität Ulm
2021
University of Geneva
2021
University of Massachusetts Boston
2021
A fundamental attribute of raft formation in cell membranes is lateral separation lipids into coexisting liquid phases. Using fluorescence microscopy, we observe spontaneous free-floating giant unilamellar vesicles. We record domains over a range composition and temperature significantly wider than previously reported. Furthermore, establish correlations between miscibility bilayers monolayers. For example, the same lipid mixtures that produce bilayer two upper critical points phase diagrams
Saturated sphingomyelin (SM) lipids are implicated in lipid rafts cell plasma membranes. Here we use fluorescence microscopy to observe coexisting liquid domains vesicles containing SM, an unsaturated phosphatidylcholine (either DOPC or POPC), and cholesterol. We note similar phase behavior a model membrane mixture without SM ($\mathrm{DOPC}/\mathrm{DPPC}/\mathrm{Chol}$), but find no micron-scale membranes of $\mathrm{POPC}/\mathrm{PSM}/\mathrm{Chol}$. delineate the onset solid phases below...
Critical fluctuations are investigated in lipid membranes near miscibility critical points bilayers composed of dioleoylphosphatidylcholine, chain perdeuterated dipalmitoylphosphatidylcholine, and cholesterol. Phase boundaries mapped over the temperature range from 10 degrees C to 60 by deuterium NMR. Tie-lines three-phase triangles evaluated across two-phase regions, respectively. In addition, a line is identified. NMR resonances broadened vicinity points, broadening attributed increased...
Significance The uptake of molecules into cells, known as endocytosis, requires membrane invagination and the formation vesicles. A version endocytosis that is independent actin polymerization aided by assembly membraneless biomolecular condensates at site invagination. Here, we show endocytic are viscoelastic bodies concentrate key proteins with prion-like domains to enable remodeling. distinct molecular grammar, namely preference for glutamine versus asparagine residues, underlies cohesive...
Plasma membranes of cells are asymmetric in both lipid and protein composition. The mechanism by which proteins on sides the membrane colocalize during signaling events is unknown but may be due to induction inner leaflet domains outer leaflet. Here we show that liquid form Montal–Mueller planar bilayers one leaflet's composition would phase-separate a symmetric bilayer other's not. Equally important, tuning second leaflet, able suppress first When present membranes, each contains regions...
Primordial cells presumably combined RNAs, which functioned as catalysts and carriers of genetic information, with an encapsulating membrane aggregated amphiphilic molecules. Major questions regarding this hypothesis include how the four bases sugar in RNA were selected from a mixture prebiotic compounds colocalized such membranes, membranes stabilized against flocculation salt water. To address these questions, we explored possibility that aggregates decanoic acid, amphiphile, interact...
Significance How did the first cells on Earth arise? In a minimal cell, membrane separates proteins and RNA from surrounding aqueous environment. Cell-like membranes spontaneously assemble simple prebiotic surfactants called fatty acids. However, acid are unstable in solutions containing salts that were likely present environments of early Earth. We find amino acids, building blocks proteins, bind to stabilize them against salts. Moreover, enhanced stabilization persists after dilution as...
Images of micrometer-scale domains in lipid bilayers have provided the gold standard model-free evidence to understand domains' shapes, sizes, and distributions. Corresponding techniques directly quantitatively assess smaller (nanoscale submicron) liquid been limited. Researchers commonly seek correlate activities membrane proteins with attributes which they reside; doing so hinges on identification characterization domains. Although some features can be probed by indirect methods, these...
Monolayers at the air-water interface were prepared from lipids extracted human red blood cells. Epifluorescence microscopy was used to show that monolayers simulating inner and outer leaflets of cell membrane form immiscible liquid phases with critical points surface pressures 21 29 dyn/cm. At these monolayer lipid density is comparable in membrane. This suggests bilayers a are near miscibility point, which should significantly affect biophysical properties
Simultaneous temperature-dependent measurements of resistance transients (RTs) and spatially resolved surface potential were made after bias switching on AlGaN/GaN high electron mobility transistors (HEMTs). We find an Ec − 0.57 eV trap, previously correlated with HEMT degradation, located in the GaN buffer not AlGaN barrier or at surface. The amplitude trap RTs depends strongly Fe-concentration buffer. Filling this occurs only under conditions where electric fields penetrate into
Near a critical point, the time scale of thermally induced fluctuations diverges in manner determined by dynamic universality class. Experiments have verified predicted three-dimensional exponents many systems, but similar experiments two dimensions been lacking for case conserved order parameter. Here we analyze time-dependent correlation functions quasi-two-dimensional lipid bilayer water to show that its dynamics agree with recently In particular, effective exponent z(eff) crosses over...