Size Analysis of Polyglutamine Protein Aggregates Using Fluorescence Detection in an Analytical Ultracentrifuge

2013 ◽  
pp. 59-71 ◽  
Author(s):  
Saskia Polling ◽  
Danny M. Hatters ◽  
Yee-Foong Mok
Keyword(s):  
Fluorescence Detection ◽  
Protein Aggregates ◽  
Size Analysis ◽  
Analytical Ultracentrifuge ◽  
Polyglutamine Protein

Fluorescence detection for the XLI analytical ultracentrifuge

2004 ◽  
Vol 108 (1-3) ◽  
pp. 165-185 ◽  
Author(s):  
Ian K. MacGregor ◽  
Arthur L. Anderson ◽  
Thomas M. Laue
Keyword(s):  
Fluorescence Detection ◽  
Analytical Ultracentrifuge

scholarly journals Tissue-specific downregulation of EDTP suppresses polyglutamine protein aggregates and extends lifespan in Drosophila

2017 ◽  
Author(s):  
Chengfeng Xiao ◽  
Shuang Qiu ◽  
R Meldrum Robertson ◽  
Laurent Seroude
Keyword(s):  
Glial Cells ◽  
Genetic Disorder ◽  
Tyrosine Phosphatase ◽  
Protein Aggregates ◽  
Protein Aggregate ◽  
Tissue Specific ◽  
Lipid Phosphatase ◽  
Muscle Tissues ◽  
Polyq Protein ◽  
Polyglutamine Protein

ABSTRACTDrosophila egg-derived tyrosine phosphatase (EDTP, also called JUMPY) is a lipid phosphatase essential in oogenesis and muscle function in the adult stage. Although mammalian JUMPY negatively regulates autophagy, loss-of-JUMPY causes muscle dysfunction and is associated with a rare genetic disorder called centronuclear myopathy. Here we show that tissue-specific downregulation of EDTP in Drosophila non-muscle tissues, particularly glial cells, suppresses the expression of polyglutamine (polyQ) protein aggregates in the same cells and improves survival. Additionally, tissue-specific downregulation of EDTP in glial cells or motoneurons extends lifespan. We demonstrate an approach to fine-tune the expression of a disease-associated gene EDTP for the removal of polyQ protein aggregate and lifespan extension in Drosophila.

scholarly journals Vinyl Phosphate-Functionalized, Magnetic, Molecularly-Imprinted Polymeric Microspheres’ Enrichment and Carbon Dots’ Fluorescence-Detection of Organophosphorus Pesticide Residues

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1770 ◽  
Author(s):  
Mao Wu ◽  
Yajun Fan ◽  
Jiawei Li ◽  
Danqing Lu ◽  
Yaping Guo ◽  
...  
Keyword(s):  
Fluorescence Detection ◽  
Pesticide Residues ◽  
Carbon Dots ◽  
Organic Phosphorus ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Molecularly Imprinted ◽  
Dual Functional

The rapid detection of organophosphorus pesticide residues in food is crucial to food safety. One type of novel, magnetic, molecularly-imprinted polymeric microsphere (MMIP) was prepared with vinyl phosphate and 1-octadecene as a collection of dual functional monomers, which were screened by Gaussian09W molecular simulation. MMIPs were used to enrich organic phosphorus, which then detected by fluorescence quenching in vinyl phosphate-modified carbon dots (CDs@VPA) originated from anhydrous citric acid. MMIPs and CDs@VPA were characterized by TEM, particle size analysis, FT-IR, VSM, XPS, adsorption experiments, and fluorescence spectrophotometry in turn. Through the fitting data from experiment and Gaussian quantum chemical calculations, the molecular recognition properties and the mechanism of fluorescence detection between organophosphorus pesticides and CDs@VPA were also investigated. The results indicated that the MMIPs could specifically recognize and enrich triazophos with the saturated adsorption capacity 0.226 mmol g−1, the imprinting factor 4.59, and the limit of recognition as low as 0.0006 mmol L−1. Under optimal conditions, the CDs@VPA sensor has shown an extensive fluorescence property with a LOD of 0.0015 mmol L−1 and the linear range from 0.0035 mmol L−1 to 0.20 mmol L−1 (R2 = 0.9988) at 390 nm. The mechanism of fluorescence detection of organic phosphorus with CDs@VPA sensor might be attributable to hydrogen bonds formed between heteroatom O, N, S, or P, and the O−H group, which led to fluorescent quenching. Meanwhile, HN−C=O and Si−O groups in CDs@VPA system might contribute to cause excellent blue photoluminescence. The fluorescence sensor was thorough successfully employed to the detection of triazophos in cucumber samples, illustrating its tremendous value towards food sample analysis in complex matrix.

scholarly journals A discontinuous Galerkin model for fluorescence loss in photobleaching of intracellular polyglutamine protein aggregates

2018 ◽  
Author(s):  
Christian Valdemar Hansen ◽  
Hans J Schroll ◽  
Daniel Wüstner
Keyword(s):  
Protein Aggregation ◽  
Discontinuous Galerkin ◽  
Computing Time ◽  
Diffusion Constant ◽  
Protein Aggregates ◽  
Computational Method ◽  
Transport Parameters ◽  
Cellular Models ◽  
Polyq Diseases ◽  
Polyglutamine Protein

Background: Intracellular phase separation and aggregation of proteins with extended poly-glutamine (polyQ) stretches are hallmarks of various age-associated neurodegenerative diseases. Progress in our understanding of such processes heavily relies on quantitative fluorescence imaging of suitably tagged proteins. Fluorescence loss in photobleaching (FLIP) is particularly well-suited to study the dynamics of protein aggregation in cellular models of Chorea Huntington and other polyQ diseases, as FLIP gives access to the full spatio-temporal profile of intensity changes in the cell geometry. In contrast to other methods, also dim aggregates become visible during time evolution of fluorescence loss in cellular compartments. However, methods for computational analysis of FLIP data are sparse, and transport models for estimation of transport and diffusion parameters from experimental FLIP sequences are missing. Results: In this paper, we present a computational method for analysis of FLIP imaging experiments of intracellular polyglutamine protein aggregates also called inclusion bodies (IBs). By this method, we are able to determine the diffusion constant and nuclear membrane permeability coefficients of polyQ proteins as well as the exchange rates between aggregates and the cytoplasm. Our method is based on a reaction-diffusion multi-compartment model defined on a mesh obtained by segmentation of the cell images from the FLIP sequence. The discontinuous Galerkin (DG) method is used for numerical implementation of our model in FEniCS, which greatly reduces the computing time. The method is applied to representative experimental FLIP sequences, and consistent estimates of all transport parameters are obtained. Conclusions: By directly estimating the transport parameters from live-cell image sequences using our new computational FLIP approach surprisingly fast exchange dynamics of mutant Huntingtin between cytoplasm and dim IBs could be revealed. This is likely relevant also for other polyQ diseases. Thus, our method allows for quantifying protein dynamics at different stages of the protein aggregation process in cellular models of neurodegeneration.

scholarly journals Fibrillar Structure and Charge Determine the Interaction of Polyglutamine Protein Aggregates with the Cell Surface

2012 ◽  
Vol 287 (35) ◽  
pp. 29722-29728 ◽  
Author(s):  
R. Sean Trevino ◽  
Jane E. Lauckner ◽  
Yannick Sourigues ◽  
Margaret M. Pearce ◽  
Luc Bousset ◽  
...  
Keyword(s):  
Cell Surface ◽  
Protein Aggregates ◽  
Fibrillar Structure ◽  
Polyglutamine Protein
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