Amyloid peptide aggregation near gold interfaces and membranes
The aggregation of peptides into amyloid fibrils, desired or undesired, plays an important role in biological systems. Amyloid-forming peptides are soluble in its native state and aggregate under certain circumstances via intermediates to insoluble fibrils with characteristic cross-β-sheet structure. This aggregation is believed to be connected with several neurodegenerative disorders such as Alzheimer’s disease (AD). However, it is not yet clear if the oligomeric intermediates or the mature fibrils are the toxic species or if amyloid fibrils are just a side product in the development of these diseases.
Continue reading “Talk by T. John at UL (June 13, 2017)”
Effects of the αC-relaxation for PEO and POM: Impact on Crystallization Process, Morphology and Reorganization Behavior
Depending on the presence or absence of an αC-relaxation it is possible to distinguish between crystal-mobile and crystal-fixed semi-crystalline polymers. Only crystal-mobile polymers own a certain chain mobility in the crystalline phase. In contrast to the crystal-fixed polymer Polycaprolactone (PCL), we analyze the impact of the αC-relaxation for two representatives of αC-mobile polymers, Polyethylenoxide (PEO) and Polyoxymethylene (POM), using different methods like SAXS and Flash-/DSC.
Continue reading “Talk by M. Schulz at MLU (May 16, 2017)”
Competition between Electrostatic and Hydrophobic Forces in the Central Core Region of Amyloid β Fibrils
Amyloidogenic peptides aggregated to large molecular assemblies are a hallmark of several diseases including Parkinson’s, Huntington’s, and Alzheimer’s disease as well as type II diabetes. Although each of these diseases gives rise to a very distinctive clinical picture, amyloid fibrils share the cross-β structure as a common structural motif. Within this motif, the peptide strands are linked via lateral β-sheet-turn-β-sheet structures that result in fiber-like aggregates with diameters of a few nanometers and lengths up to several micrometers.
The central question that will be addressed is how electrostatic and hydrophobic interactions compete within the central core region of Aβ(1-40) fibrils. Continue reading “Talk by F. Hoffmann at MLU (April 4, 2017)”