Next-Generation AUC

Gorbet, Gary E.; Pearson, Joseph; Demeler, Aysha K.; Cölfen, Helmut; Demeler, Borries

doi:10.1016/bs.mie.2015.04.013

Cited by 36 publications

(23 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, slow calculations and lack of parallelization capabilities in Sedfit make this method impractical for the analysis of MWL data available from the new generation of AUC. 8, 18, 32, 33 …”

Section: Resultsmentioning

confidence: 99%

2D analysis of polydisperse core–shell nanoparticles using analytical ultracentrifugation

Walter

Gorbet

Akdas

et al. 2017

Analyst

Self Cite

View full text Add to dashboard Cite

Accurate knowledge of size, density and composition of nanoparticles (NPs) is of major importance for their applications. In this work the hydrodynamic characterization of polydisperse core-shell NPs by means of analytical ultracentrifugation (AUC) is addressed. AUC is one of the most accurate techniques for the characterization of NPs in the liquid phase because it can resolve particle size distributions (PSDs) with unrivaled resolution and detail. Small NPs have to be considered as core-shell systems when dispersed in a liquid since a solvation layer and stabilizer shell will significantly contribute to the particle’s hydrodynamic diameter and effective density. AUC measures the sedimentation and diffusion transport of the analytes, which are affected by the core-shell compositional properties. This work demonstrates that polydisperse and thus widely distributed NPs pose significant challenges for current state-of-the-art data evaluation methods. Existing methods either have insufficient resolution or do not correctly reproduce the core-shell properties. First, we investigate the performance of different data evaluation models by means of simulated data. Then, we propose a new methodology to address the core-shell properties of NPs. This method is based on the parametrically constrained spectrum analysis and offers complete access to the size and effective density of polydisperse NPs. Our study is complemented using experimental data derived for ZnO and CuInS2 NPs, which do not have a monodisperse PSD. For the first time, the size and effective density of such structures can be resolved with high resolution by means of a two-dimensional AUC analysis approach.

show abstract

Section: Resultsmentioning

confidence: 99%

2D analysis of polydisperse core–shell nanoparticles using analytical ultracentrifugation

Walter

Gorbet

Akdas

et al. 2017

Analyst

Self Cite

View full text Add to dashboard Cite

show abstract

“…As shown recently, MWL analysis can provide access to hydrodynamic and optical properties simultaneously by means of sedimentation velocity data. 5,10,12 For gold nanorods it was demonstrated that MWL-AUC can give rise to the size and shape dependent optical properties using speed ramp experiments. 5 However, quantitative information was not yet accessible.…”

Section: Determination Of Size Dependent Optical Properties Of Gold Npsmentioning

confidence: 99%

“…Hence, the development of new evaluation procedures and respective software capable of MWL-analysis is highly attractive for two reasons: First, it will allow for a direct correlation of hydrodynamic and optical properties even in complex mixtures as it was recently developed for sedimentation velocity data. 10,12 In contrast to sedimentation velocity experiments typically conducted at a constant speed or a series of discrete increasing rotor speeds, speed ramp experiments offer a much higher dynamic range. The capability to qualitatively distinguish between different species of gold nanorods has been recently shown.…”

Section: Introductionmentioning

confidence: 99%

“…5,10 Manifold software packages developed for AUC allow for accurate size analysis and even shape, density and optical information of NPs in complex mixtures became accessible using AUC. 3,11,12 Even though many NP systems benefit from these investigations, the existing evaluation procedures still require further developments. One challenge is the evaluation of broad PSDs, where many other techniques, such as the most commonly applied dynamic light scattering (DLS), fail.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic range multiwavelength particle characterization using analytical ultracentrifugation

Walter

Peukert

2016

Nanoscale

View full text Add to dashboard Cite

We demonstrate how a sophisticated data analysis methodology enables us to perform multiwavelength evaluations of dynamic rotor speed gradient experiments obtained by analytical ultracentrifugation equipped with a multiwavelength detector. Our data evaluation tool HDR-MULTIFIT allows for the accurate analysis of sedimentation coefficient distributions which can be converted to particle size distributions. By means of multiwavelength evaluation, species dependent extinction spectra can be determined even for complex mixtures. Moreover, optical and hydrodynamic properties can be correlated for spherical particles of known optical properties applying multiwavelength evaluation and Mie's theory leading to a significant increase in the dynamic range of the experiment. We provide the theoretical background about the operation principle of our methodology and compare the performance of the multiwavelength analysis to the conventional single wavelength analysis as it is applied in turbidity analysis. We validate our technique using NIST traceable reference particles and show that our technique is universally applicable to materials of known and unknown optical properties, thus clearly extending the possibilities of particle analysis.

show abstract

“…SV data were analyzed with UltraScan-III [40] All calculations were performed on the XSEDE UltraScan Science Gateway using high-performance computing resources at the Texas Advanced Computing Center, at the San Diego Supercomputing Center, and at the Bioinformatics Core Facility at the University of Texas Health Science Center at San Antonio. All measurements were made in 20 mM sodium phosphate buffer, pH 7.8, supplemented with 0.15 M or 0.3 mM NaCl.…”

Section: Methodsmentioning

confidence: 99%

A new mode of SAM domain mediated oligomerization observed in the CASKIN2 neuronal scaffolding protein

et al. 2016

Self Cite

View full text Add to dashboard Cite

BackgroundCASKIN2 is a homolog of CASKIN1, a scaffolding protein that participates in a signaling network with CASK (calcium/calmodulin-dependent serine kinase). Despite a high level of homology between CASKIN2 and CASKIN1, CASKIN2 cannot bind CASK due to the absence of a CASK Interaction Domain and consequently, may have evolved undiscovered structural and functional distinctions.ResultsWe demonstrate that the crystal structure of the Sterile Alpha Motif (SAM) domain tandem (SAM1-SAM2) oligomer from CASKIN2 is different than CASKIN1, with the minimal repeating unit being a dimer, rather than a monomer. Analytical ultracentrifugation sedimentation velocity methods revealed differences in monomer/dimer equilibria across a range of concentrations and ionic strengths for the wild type CASKIN2 SAM tandem and a structure-directed double mutant that could not oligomerize. Further distinguishing CASKIN2 from CASKIN1, EGFP-tagged SAM tandem proteins expressed in Neuro2a cells produced punctae that were distinct both in shape and size.ConclusionsThis study illustrates a new way in which neuronal SAM domains can assemble into large macromolecular assemblies that might concentrate and amplify synaptic responses.Electronic supplementary materialThe online version of this article (doi:10.1186/s12964-016-0140-3) contains supplementary material, which is available to authorized users.

show abstract

Next-Generation AUC

Cited by 36 publications

References 20 publications

2D analysis of polydisperse core–shell nanoparticles using analytical ultracentrifugation

2D analysis of polydisperse core–shell nanoparticles using analytical ultracentrifugation

Dynamic range multiwavelength particle characterization using analytical ultracentrifugation

A new mode of SAM domain mediated oligomerization observed in the CASKIN2 neuronal scaffolding protein

Contact Info

Product

Resources

About