Amyloid diseases, including Alzheimer's and prion diseases, are each associated with unbranched protein fibrils. Each fibril is made of a particular protein, yet they share common properties. One such property is nucleation-dependent fibril growth. Monomers of amyloid-forming proteins can remain in dissolved form for long periods, before rapidly assembly into fibrils. The lag before growth has ...

Amyloid diseases, including Alzheimer’s and prion diseases, are each associated with unbranched protein fibrils. Each fibril is made of a particular protein, yet they share common properties. One such property is nucleation-dependent fibril growth. Monomers of amyloid-forming proteins can remain in dissolved form for long periods, before rapidly assembly into fibrils. The lag before growth has ...

Polymorphism is a key feature of amyloid fibril structures but it remains challenging to explain these variations for a particular sample. Here, we report electron cryomicroscopy-based reconstructions from different fibril morphologies formed by a peptide fragment from an amyloidogenic immunoglobulin light chain. The observed fibril morphologies vary in the number and cross-sectional arrangemen...

α-Synuclein (140 amino acids), one of the causative proteins of Parkinson's disease, forms amyloid fibrils in brain neuronal cells. In order to further explore the contributions of the C-terminal region of α-synuclein in fibril formation and also to understand the overall mechanism of fibril formation, we reduced the number of negatively charged residues in the C-terminal region using mutagenes...

Mineralized collagen fibrils are composed of tropocollagen molecules and mineral crystals derived from hydroxyapatite to form a composite material that combines optimal properties of both constituents and exhibits incredible strength and toughness. Their complex hierarchical structure allows collagen fibrils to sustain large deformation without breaking. In this study, we report a mesoscale mod...

Polymorphism is a key feature of amyloid fibril structures but it remains challenging to explain these variations for a particular sample. Here, we report electron cryomicroscopy-based reconstructions from different fibril morphologies formed by a peptide fragment from an amyloidogenic immunoglobulin light chain. The observed fibril morphologies vary in the number and cross-sectional arrangemen...

Type I collagen is the predominant collagen in mature tendons and ligaments, where it gives them their load-bearing mechanical properties. Fibrils of type I collagen are formed by the packing of polypeptide triple helices. Higher-order structures like fibril bundles and fibers are assembled from fibrils in the presence of other collagenous molecules and noncollagenous molecules. Curiously, howe...

This article investigates the theoretical basis for differences in visible light transmission through the human cornea as a function of distance from the center. Experimentally, transmission decreases approximately linearly up to 3 mm from the central axis, then quadratically beyond this. It is known that collagen fibril number density and collagen fibril radii change from the central region to...

We performed mass-per-length (MPL) measurements and electron cryomicroscopy (cryo-EM) with 3D reconstruction on an Abeta(1-42) amyloid fibril morphology formed under physiological pH conditions. The data show that the examined Abeta(1-42) fibril morphology has only one protofilament, although two protofilaments were observed with a previously studied Abeta(1-40) fibril. The latter fibril was re...

Connective tissue mechanical behavior is primarily determined by the composition and organization of collagen. In ligaments and tendons, type I collagen is the principal structural element of the extracellular matrix, which acts to transmit force between bones or bone and muscle, respectively. Therefore, characterization of collagen fibril morphology and organization in fetal and skeletally mat...