0000000000700628

AUTHOR

Marco Van De Weert

showing 3 related works from this author

Polysorbate 80 controls Morphology, structure and stability of human insulin Amyloid-Like spherulites

2022

AbstractAmyloid protein aggregates are not only associated with neurodegenerative diseases and may also occur as unwanted by-products in protein-based therapeutics. Surfactants are often employed to stabilize protein formulations and reduce the risk of aggregation. However, surfactants alter protein-protein interactions and may thus modulate the physicochemical characteristics of any aggregates formed. Human insulin aggregation was induced at low pH in the presence of varying concentrations of the surfactant polysorbate 80. Various spectroscopic and imaging methods were used to study the aggregation kinetics, as well as structure and morphology of the formed aggregates. Molecular dynamics s…

Amyloid-like Spherulites Fluorescence Lifetime Imaging Aggregate Stability Polysorbate 80 Protein FormulationsAmyloidMorphology (linguistics)AmyloidChemistryInsulinmedicine.medical_treatmentIntermolecular forcePolysorbatesPolyvinyl alcoholSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsBiomaterialsSurface-Active Agentschemistry.chemical_compoundMolecular dynamicsColloid and Surface ChemistryPulmonary surfactantCritical micelle concentrationmedicineBiophysicsHumansInsulinMicelles
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Secondary nucleation and accessible surface in insulin amyloid fibril formation.

2008

At low pH insulin is highly prone to self-assembly into amyloid fibrils. The process has been proposed to be affected by the existence of secondary nucleation pathways, in which already formed fibrils are able to catalyze the formation of new fibrils. In this work, we studied the fibrillation process of human insulin in a wide range of protein concentrations. Thioflavin T fluorescence was used for its ability to selectively detect amyloid fibrils, by mechanisms that involve the interaction between the dye and the accessible surface of the fibrils. Our results show that the rate of fibrillation and the Thioflavin T fluorescence intensity saturate at high protein concentration and that, surpr…

AmyloidSurface Propertiesmedicine.medical_treatmentKineticsNucleationmacromolecular substancesProtein aggregationFibrilstochastic processchemistry.chemical_compoundMaterials ChemistrymedicineHumansInsulinBenzothiazolesPhysical and Theoretical ChemistryFibrillationChemistryInsulinFluorescenceSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Surfaces Coatings and FilmsCrystallographyKineticsThiazolesBiophysicsThioflavin TThioflavinmedicine.symptomProtein aggregationThe journal of physical chemistry. B
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Thioflavin T Hydroxylation at Basic pH and Its Effect on Amyloid Fibril Detection

2008

The fluorescent dye thioflavin T (ThT) is commonly used for in situ amyloid fibril detection. In this work, we focused on the spectroscopic properties and chemical stability of ThT in aqueous solution as a function of pH, temperature, and dye concentration. A reversible hydroxylation process occurs in alkaline solutions, which was characterized using a combination of UV-vis absorption spectroscopy, proton NMR, and density functional theory (DFT). On the basis of these studies, we propose a chemical structure for the hydroxylated form. Finally, by means of fluorescence spectroscopy, ThT hydroxylation effects on in situ amyloid detection have been investigated, providing new insights on the e…

AmyloidMagnetic Resonance SpectroscopyAqueous solutionTemperatureThioflavin T AmyloidHydrogen-Ion ConcentrationHydroxylationPhotochemistryFibrilFluorescenceFluorescence spectroscopySurfaces Coatings and FilmsHydroxylationKineticsThiazoleschemistry.chemical_compoundchemistryMaterials ChemistryProton NMROrganic chemistrySpectrophotometry UltravioletThioflavinChemical stabilityBenzothiazolesPhysical and Theoretical ChemistryThe Journal of Physical Chemistry B
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