Browse
Submit Data
Databases
API
Help

Dataset Information

13 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Optimized reverse micelle surfactant system for high-resolution NMR spectroscopy of encapsulated proteins and nucleic acids dissolved in low viscosity fluids.

ABSTRACT: An optimized reverse micelle surfactant system has been developed for solution nuclear magnetic resonance studies of encapsulated proteins and nucleic acids dissolved in low viscosity fluids. Comprising the nonionic 1-decanoyl-rac-glycerol and the zwitterionic lauryldimethylamine-N-oxide (10MAG/LDAO), this mixture is shown to efficiently encapsulate a diverse set of proteins and nucleic acids. Chemical shift analyses of these systems show that high structural fidelity is achieved upon encapsulation. The 10MAG/LDAO surfactant system reduces the molecular reorientation time for encapsulated macromolecules larger than ~20 kDa leading to improved overall NMR performance. The 10MAG/LDAO system can also be used for solution NMR studies of lipid-modified proteins. New and efficient strategies for optimization of encapsulation conditions are described. 10MAG/LDAO performs well in both the low viscosity pentane and ultralow viscosity liquid ethane and therefore will serve as a general surfactant system for initiating solution NMR studies of proteins and nucleic acids.

SUBMITTER: Dodevski I

PROVIDER: S-EPMC3969725 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

High-resolution NMR spectroscopy of encapsulated proteins dissolved in low-viscosity fluids.

Project description:High-resolution multi-dimensional solution NMR is unique as a biophysical and biochemical tool in its ability to examine both the structure and dynamics of macromolecules at atomic resolution. Conventional solution NMR approaches, however, are largely limited to examinations of relatively small (<25kDa) molecules, mostly due to the spectroscopic consequences of slow rotational diffusion. Encapsulation of macromolecules within the protective nanoscale aqueous interior of reverse micelles dissolved in low viscosity fluids has been developed as a means through which the 'slow tumbling problem' can be overcome. This approach has been successfully applied to diverse proteins and nucleic acids ranging up to 100kDa, considerably widening the range of biological macromolecules to which conventional solution NMR methodologies may be applied. Recent advances in methodology have significantly broadened the utility of this approach in structural biology and molecular biophysics.

| S-EPMC4127067 | biostudies-literature

Reverse Micelle Encapsulation of Proteins for NMR Spectroscopy.

Project description:Reverse micelle (RM) encapsulation of proteins for NMR spectroscopy has many advantages over standard NMR methods such as enhanced tumbling and improved sensitivity. It has opened many otherwise difficult lines of investigation including the study of membrane-associated proteins, large soluble proteins, unstable protein states, and the study of protein surface hydration dynamics. Recent technological developments have extended the ability of RM encapsulation with high structural fidelity for nearly all proteins and thereby allow high-quality state-of-the-art NMR spectroscopy. Optimal conditions are achieved using a streamlined screening protocol, which is described here. Commonly studied proteins spanning a range of molecular weights are used as examples. Very low-viscosity alkane solvents, such as propane or ethane, are useful for studying very large proteins but require the use of specialized equipment to permit preparation and maintenance of well-behaved solutions under elevated pressure. The procedures for the preparation and use of solutions of RMs in liquefied ethane and propane are described. The focus of this chapter is to provide procedures to optimally encapsulate proteins in reverse micelles for modern NMR applications.

| S-EPMC6487188 | biostudies-literature

A surfactant-stripped cabazitaxel micelle formulation optimized with accelerated storage stability.

Project description:Pluronic (Poloxomer) micelles can solubilize cabazitaxel (CTX), a second-generation taxane, and then be subjected to low-temperature "surfactant-stripping" to selectively remove loose and free surfactant, thereby increasing the drug-to-surfactant ratio. We previously found that the addition of certain other co-loaded hydrophobic cargo to the micelles can result in stabilized, surfactant-stripped cabazitaxel (sss-CTX) micelles, which resist drug aggregation in aqueous storage, a common challenge for taxanes. Here, we show that elevated temperatures can accelerate the aggregation of sss-CTX micelles, thereby enabling rapid optimization of formulations with respect to the type and ratio of co-loader used for stabilization. A sss-CTX micelle formulation was developed using mifepristone as the co-loader, at a 60% mass ratio to the CTX. Drug release, hemolysis and complement activation were investigated in vitro. Microtubule stabilization and in vitro cytotoxicity were similar for sss-CTX and a conventional Tween-80 micelle formulation. In vivo pharmacokinetics also revealed similar blood circulation of the two formulations. In subcutaneous Lewis lung carcinoma tumors, as well as in an aggressive mouse model of malignant pleural effusion, sss-CTX showed a similar therapeutic effect as the Tween-80 based formulation. Altogether, these data show that sss-CTX can achieve similar efficacy as conventional Tween-80 formulations, albeit with substantially higher drug-to-surfactant ratio and with capability of extended aqueous storage.

| S-EPMC7695035 | biostudies-literature

Reverse micelle encapsulation of membrane-anchored proteins for solution NMR studies.

Project description:Perhaps 5%-10% of proteins bind to membranes via a covalently attached lipid. Posttranslational attachment of fatty acids such as myristate occurs on a variety of viral and cellular proteins. High-resolution information about the nature of lipidated proteins is remarkably sparse, often because of solubility problems caused by the exposed fatty acids. Reverse micelle encapsulation is used here to study two myristoylated proteins in their lipid-extruded states: myristoylated recoverin, which is a switch in the Ca(2+) signaling pathway in vision, and the myristoylated HIV-1 matrix protein, which is postulated to be targeted to the plasma membrane through its binding to phosphatidylinositol-4,5-bisphosphate. Both proteins have been successfully encapsulated in the lipid-extruded state and high-resolution NMR spectra obtained. Both proteins bind their activating ligands in the reverse micelle. This approach seems broadly applicable to membrane proteins with exposed fatty acid chains that have eluded structural characterization by conventional approaches.

| S-EPMC2876244 | biostudies-literature

A facile surfactant critical micelle concentration determination.

Project description:Liquid surface curvature variations in microplate wells due to different liquid surface tension cause significant signal change in spectroscopic measurement using a plate reader with a vertical detecting light beam. The signals have been quantitated and used to develop a method for facile surfactant critical micelle concentration determination.

| S-EPMC3228408 | biostudies-literature

Odd viscosity in chiral active fluids.

Project description:We study the hydrodynamics of fluids composed of self-spinning objects such as chiral grains or colloidal particles subject to torques. These chiral active fluids break both parity and time-reversal symmetries in their non-equilibrium steady states. As a result, the constitutive relations of chiral active media display a dissipationless linear-response coefficient called odd (or equivalently, Hall) viscosity. This odd viscosity does not lead to energy dissipation, but gives rise to a flow perpendicular to applied pressure. We show how odd viscosity arises from non-linear equations of hydrodynamics with rotational degrees of freedom, once linearized around a non-equilibrium steady state characterized by large spinning speeds. Next, we explore odd viscosity in compressible fluids and suggest how our findings can be tested in the context of shock propagation experiments. Finally, we show how odd viscosity in weakly compressible chiral active fluids can lead to density and pressure excess within vortex cores.

| S-EPMC5691086 | biostudies-other

Mixing high-viscosity fluids via acoustically driven bubbles.

Project description:We present an acoustofluidic micromixer which can perform rapid and homogeneous mixing of highly viscous fluids in the presence of an acoustic field. In this device, two high-viscosity polyethylene glycol (PEG) solutions were co-injected into a three-inlet PDMS microchannel with the center inlet containing a constant stream of nitrogen flow which forms bubbles in the device. When these bubbles were excited by an acoustic field generated via a piezoelectric transducer, the two solutions mixed homogenously due to the combination of acoustic streaming, droplet ejection, and bubble eruption effects. The mixing efficiency of this acoustofluidic device was evaluated using PEG-700 solutions which are ~106 times more viscous than deionized (DI) water. Our results indicate homogenous mixing of the PEG-700 solutions with a ~0.93 mixing index. The acoustofluidic micromixer is compact, inexpensive, easy to operate, and has the capacity to mix highly viscous fluids within 50 milliseconds.

| S-EPMC6777744 | biostudies-literature

Toward understanding polymer micelle stability: Density ultracentrifugation offers insight into polymer micelle stability in human fluids.

Project description:Micelles, as a class of drug delivery systems, are underrepresented among United States Food and Drug Administration approved drugs. A lack of clinical translation of these systems may be due to, in part, to a lack of understanding of micelle interactions with biologic fluids following injection. Despite the limited clinical translation, micelles remain an active area of research focus and pre-clinical development. The goal of the present study was to examine the stability of amphiphilic block copolymer micelles in biologic fluids to identify the properties and components of biologic fluids that influence micelle stability. Micelle stability, measured via Förster resonance energy transfer-based fluorescent spectrometry, was complemented with density ultracentrifugation to reveal the colocalized, or dissociated, state of the dye cargo after exposure to human biologic fluids. Polymeric micelles composed of poly(ethylene glycol-block-caprolactone) (mPEG-CL) and poly(ethylene glycol-block-lactide) (mPEG-LA) were unstable in fetal bovine serum, human serum and synovial fluid, with varying levels of instability observed in ascites and pleural fluid. All polymeric micelles exhibited stability in cerebrospinal fluid, highlighting the potential for local cerebro-spinal administration of micelles. Interestingly, mPEG2.2k-CL3.1k and mPEG2k-LA2.7k micelles favored dissolution whereas mPEG5.4k-LA28.5k micelles favored stability. Taken together, our data offers both quantitative and qualitative evidence for micelle stability within human biologic fluids and offers evidence of polymer micelle instability in biologic fluids that is not explained by either total protein content or total unsaturated lipid content. The results help to identify potential sites for local delivery where stability is maintained.

| S-EPMC6958513 | biostudies-literature

The Impact of Micelle Formation on Surfactant Adsorption-Desorption.

Project description:The monomer-micelle equilibrium is shown to be responsible for an asymmetry between surfactant adsorption and desorption rates. When a solution containing micelles is brought into contact with a solid surface, the micelles dissociate to supply monomers that adsorb to the surface. When the same surface is subsequently exposed to a surfactant-free solution, desorption occurs slowly because of the higher affinity of the monomers to remain to the surface than to form micelles. As a result, the number of monomers that desorb is limited by the critical micelle concentration (CMC) of the surfactant. This effect is particularly pronounced for surfactants with low CMC values and in systems with high surface-to-volume ratios, such as porous media. A generic model is developed and applied to simulate the Ca2+-mediated adsorption and desorption of surfactants in limestone cores.

| S-EPMC7841946 | biostudies-literature

Surfactant Self-Assembling and Critical Micelle Concentration: One Approach Fits All?

Project description:Critical micelle concentration (CMC) is the main chemical-physical parameter to be determined for pure surfactants for their characterization in terms of surface activity and self-assembled aggregation. The CMC values can be calculated from different techniques (e.g., tensiometry, conductivity, fluorescence spectroscopy), able to follow the variation of a physical property with surfactant concentrations. Different mathematical approaches have been applied for the determination of CMC values from the raw experimental data. Most of them are independent of the operator, despite not all of the fitting procedures employed so far can be applied in all techniques. In this experimental work, the second derivative of the experimental data has been proposed as a unique approach to determine the CMC values from different techniques (tensiometry, conductimetry, densimetry, spectrofluorimetry, and high-resolution ultrasound spectroscopy). To this end, the CMC values of five different surfactants, specifically three anionic (sodium dodecyl sulfate, sodium deoxycolate, and N-lauroyl sarcosinate) and two nonionic, such as polyethylene glycol ester surfactants [polyethylenglicol (8) monostearate and polyethylenglicol (8) monolaurate], have been determined by this approach. The "second-derivate" approach provides a reliable determination of the CMC values among all of the techniques investigated, which were comparable to those calculated by the other operator-free routinely methods employed, such as segmental linear regression or Boltzmann regression. This study also highlighted the strengths and shortcomings of each technique over the others, providing an overview of the CMC values of commonly used anionic and nonionic surfactants in the pharmaceutical field, determined by employing different experimental approaches.

| S-EPMC8007100 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data