We investigate in vitro fibrillation kinetics of the hormone peptide glucagon at various concentrations using confocal microscopy and determine the glucagon fibril persistence length 60μm. At all concentrations we observe that periods of individual fibril growth are interrupted by periods of stasis. The growth probability is large at high and low concentrations and is reduced for intermediate g...

Amyloid associated with seven sclerotic and two normal aortic and mitral valves was studied. The sclerotic valve amyloid contained microfibrils with typical random orientation and a fibril width of 9.5-12.5 nm. The amyloid deposits demonstrated permanganate-resistant Congophilia and contained the amino acid tryptophan. Immunofluorescence studies showed P-component in amyloid deposits of 6 of 7 ...

Sodium dodecyl sulphate (SDS) was used to weaken both the electrostatic and the hydrophobic interactions during collagen fibrillogenesis in vitro. The rate and extent of fibril formation as well as fibril morphology were affected by SDS concentration. Both the formation of large fibrils at 0.3 mM-SDS and the complete cessation of fibril formation at 0.5 mM-SDS were considered to be the result o...

Fibrin molecules polymerize to double-stranded fibrils by intermolecular end-to-middle domain pairing of complementary polymerization sites, accompanied by fibril branching to form a clot network. Mass/length measurements on scanning transmission electron microscopic images of fibrils comprising branch points showed two types of junctions. Tetramolecular junctions occur when two fibrils converg...

Assembly of normally soluble proteins into amyloid fibrils is a cause or associated symptom of numerous human disorders, including Alzheimer's and the prion diseases. We report molecular-level simulation of spontaneous fibril formation. Systems containing 12-96 model polyalanine peptides form fibrils at temperatures greater than a critical temperature that decreases with peptide concentration a...

In this paper, we study the stability of an initially straight elastic fibril clamped at one end, while the other end is subjected to a constant normal compressive force and a prescribed shear displacement. We found the buckling load of a sheared fibril to be always less than the Euler buckling load. Furthermore, if the end of the fibril loses adhesion, then the buckling load can be considerabl...

8. Electron microscopy provides evidence for an SA-tO-Sc transition in many other collagen fibrils (Stolinski & Breathnach, 1977; Lillie et al., 1977, and references therein). 9. An SA liquid-crystal model for the structure of the collagen fibril explains how hydroxyapatite crystals increase its Young’s modulus in bone (D. W. L. Hukins, unpublished work). The liquid-crystal properties of the co...

....................................................................................................................................1 1. Computational studies of protein folding and aggregation ..........................................3 1.1 Overview ....................................................................................................................3 1.2 Protein structure..........

We have investigated the self-assembly of fluorenylmethoxycarbonyl-conjugated dialanine (Fmoc-AA) molecules using combined computational and experimental approaches. Fmoc-AA gels were characterized using transmission electron microscopy (TEM), circular dichroism (CD), Fourier transform infrared (FTIR), and wide-angle X-ray scattering (WAXS). Computationally, we simulated the assembly of Fmoc-AA...

Determining the structure of cartilage collagen fibrils will provide insights into how mutations in collagen genes affect cartilage formation during skeletal morphogenesis and understanding the mechanism of fibril growth. The fibrils are indeterminate in size, heteropolymeric, and highly cross-linked, which make them refractory to analysis by conventional high-resolution structure determination...