A5046541656- Lipid Membrane Structure and Behavior
- Surfactants and Colloidal Systems
- Protein Structure and Dynamics
- Spectroscopy and Quantum Chemical Studies
- Sphingolipid Metabolism and Signaling
- Cholesterol and Lipid Metabolism
- Supramolecular Self-Assembly in Materials
- Neuroscience and Neuropharmacology Research
- Liquid Crystal Research Advancements
- Nonlinear Dynamics and Pattern Formation
- Parkinson's Disease Mechanisms and Treatments
- RNA Interference and Gene Delivery
- Food Chemistry and Fat Analysis
- Material Dynamics and Properties
- Drug Transport and Resistance Mechanisms
- Nuclear Receptors and Signaling
- Receptor Mechanisms and Signaling
- Advanced Fluorescence Microscopy Techniques
- Force Microscopy Techniques and Applications
- Metabolomics and Mass Spectrometry Studies
- Neuroinflammation and Neurodegeneration Mechanisms
- Thermodynamic properties of mixtures
- Gold and Silver Nanoparticles Synthesis and Applications
- Research on Leishmaniasis Studies
- Bone Metabolism and Diseases
Texas Tech University
2014-2025
Sun Yat-sen University
2021-2025
Texas Tech University Health Sciences Center
2023
Chapman University
2023
Chinese Academy of Medical Sciences & Peking Union Medical College
2014-2023
Tianjin University of Traditional Chinese Medicine
2017-2023
King Saud University
2023
Peking Union Medical College Hospital
2014-2023
Clinical Trials New Zealand
2021
University of Jyväskylä
2006-2010
We recently reported the equilibrium maximum solubility of cholesterol in a lipid bilayer, chi*chol, to be 0.66 four different phosphatidylcholines, and 0.51 phosphatidylethanolamine (Huang, J.,J.T. Buboltz, G. W. Feigenson. 1999. Biochim. Biophys. Acta. press). Here we present model cholesterol-phospholipid mixing that explains these observed values chi*chol. Monte Carlo simulations show pairwise-additivity nearest-neighbor interactions is inadequate describe all chi*chol values. Instead,...
In any lipid bilayer membrane, there is an upper limit on the cholesterol concentration that can be accommodated within structure; excess will precipitate as crystals of pure monohydrate. This solubility a well-defined quantity. It first-order phase boundary in phospholipid/cholesterol diagram. There are many different limits literature, but no clear picture has emerged unify disparate results. We have studied effects sample preparation methods apparent experimental limit. find artifactual...
The condensing effect of cholesterol in dioleoylphosphatidylcholine (DOPC) lipid bilayers was systematically investigated via atomistic molecular dynamics (MD) simulation. Fourteen independent 200 ns simulations, spanning the entire range mole fraction (xc) DOPC (i.e., from xc = 0 to 0.66), were performed at 323 K. areas occupied by and different distances bilayer center analyzed using a slicing method based on VDW radii atoms. Curiously, while average area per tilt angle, with respect...
Cholesterol plays a vital role in determining the physiochemical properties of cell membranes. However, detailed nature cholesterol-lipid interactions is subject ongoing debate. Existing conceptual models, including Condensed Complex Model, Superlattice and Umbrella identify different molecular mechanisms as key to interactions. In this work, compositional dependence chemical potential cholesterol cholesterol/phosphatidylcholine mixtures was systematically measured at high resolution 37...
Ischemic stroke, accounting for the majority of stroke events, significantly contributes to global morbidity and mortality. Vascular recanalization therapies, namely intravenous thrombolysis mechanical thrombectomy, have emerged as critical interventions, yet their success hinges on timely application patient-specific factors. This review focuses early phase pathophysiological mechanisms ischemic nuances recanalization. It highlights dual role neutrophils in tissue damage repair, involvement...
Wide angle x-ray scattering (WAXS) from oriented lipid multilayers was used to study the effect of adding cholesterol (Chol) or 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) gel-phase 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers.Small quantities (X < 0.10 mole fraction) both molecules disrupt tight packing tilted chains pure DPPC, forming a more disordered, untilted phase.The addition larger DOPC causes sample phase-separate into gel phase, characterized by narrow WAXS peak,...
Sterol biosynthesis is a crucial pathway in eukaryotes leading to the production of cholesterol animals and various C24-alkyl sterols (ergostane-based sterols) fungi, plants, trypanosomatid protozoa. Sterols are important membrane components precursors for synthesis powerful bioactive molecules, including steroid hormones mammals. Their functions pathogenic protozoa not well characterized, which limits development sterol inhibitors as drugs. Here we investigated role C14α-demethylase (C14DM)...
Limited knowledge on the exact functions of ergostane-based sterols has hampered application sterol synthesis inhibitors against trypanosomatid parasites. Sterol methyltransferase (SMT) is directly involved in parasite-specific C24-methylated sterols, including ergosterol and 5-dehydroepisterol. While pharmacological studies hint at its potential as a drug target trypanosomatids, direct evidence for cellular function essentiality SMT lacking. Here, we characterized knockout mutants their...
The mixing of phosphatidylserine (PS) and phosphatidylcholine (PC) in fluid bilayer model membranes was studied by measuring binding aqueous Ca2+ ions. measured [Ca2+]aq used to derive the activity coefficient for PS, gamma lipid mixture. For (16:0, 18:1) PS binary mixtures with either 18:1)PC, (14:1, 14:1)PC, or (18:1, > 1; i.e., is nonideal, PC clustered rather than randomly distributed, despite electrostatic repulsion between headgroups. To understand better this behavior, Monte Carlo...
The effect of brain ceramide on the maximum solubility cholesterol in ternary mixtures 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), cholesterol, and was investigated at 37 °C by a oxidase (COD) reaction rate assay optical microscopy. COD showed sharp increase chemical potential as mole fraction approaches limit. A decline found after formation crystals. POPC bilayers determined to be 68 ± 2 mol % We that has much higher affinity for ordered than decreases with content. More...
The instability of cholesterol clusters and the Umbrella effect in dipalmitoylphosphatidylcholine (DPPC) dioleoylphosphatidylcholine (DOPC) lipid bilayers were investigated via atomistic molecular dynamics (MD) simulation. Cholesterol phosphatidylcholine (PC) are found to be very unstable readily disperse into monomers. This results from difficulty bilayer system preventing water exposure cholesterol's bulky hydrophobic bodies a cluster. responds artificially arranged several interesting...
Diacylglycerols (DAGs) are important second messengers in biomembranes, and they can activate protein kinase C many other enzymes receptors. However, their interactions with cholesterol lipids have not been previously studied using molecular dynamics (MD) simulation. In this study, nine independent atomistic MD simulations were performed to specifically investigate the between di16:0DAG, 16:0,18:1-phosphatidylcholine (POPC), cholesterol. Despite substantial differences chemical structure,...
The purpose of this study was to investigate the effects volatile anesthetic agents isoflurane and sevoflurane, at clinically relevant concentrations, on fluidity lipid membranes permeability blood-brain barrier (BBB). We analyzed in vitro or ketamine using erythrocyte ghosts (sodium fluorescein permeability), monolayers brain microvascular endothelial cells ([<sup>13</sup>C]sucrose liposomes (fluorescence anisotropy). Additionally, we determined 30-minute exposure mice tight junction...
Experimental evidences have indicated that cholesterol may adapt highly regular lateral distributions (i.e., superlattices) in a phospholipid bilayer. We investigated the formations of superlattices at mole fraction 0.154, 0.25, 0.40, and 0.5 using Monte Carlo simulation. found general, conventional pairwise-additive interactions cannot produce superlattices. Instead, multibody (nonpairwise) interaction is required. Cholesterol superlattice formation reveals although overall between...
The membrane fluidity increases induced by popular anesthetic agents (propofol, isoflurane, sevoflurane, and ketamine/xylazine) were measured at the clinical supra-clinical concentrations in red blood cell (RBC) as well four model membranes. Membrane changes monitored using excimer/monomer (E/M) ratio of dipyrene-PC fluorescence anisotropies DPH-PC TMA-DPH. Propofol, sevoflurane isoflurane increased instantaneously. largest increase occurs membranes made saturated lipids. RBCs labeled with...