Proteins fibrils

Lomakin A, Chung DS, Benedek GB, Kirschner DA, Teplow DB. On the nucleation and growth of amyloid beta protein fibrils detection of nuclei... 

Key Words Structurally and/or dynamically heterogeneous systems, Hydrogels, Protein fibrils, Membrane proteins, Dynamic aspects... 

Even though, structure and dynamics are most important to characterize hydrogels, protein fibrils, and membrane proteins, they cannot be simultaneously determined. We emphasize here the importance of the dynamic aspect mainly available from NMR measurements at ambient temperature, even though structural data can be obtained more easily at lower temperatures under suppressed dynamics. 

We have emphasized here that the dynamic aspects of NMR studies are crucially important for structurally or dynamically heterogeneous systems such as synthetic or natural hydrogels, protein fibrils and membrane proteins. This is in order to characterize their unique chemical, physical and biological properties in terms of a variety of fluctuation frequencies, including high (> 108 Hz) or intermediate (104-105 Hz) frequency fluctuations. It turns out that the presence of the high-frequency motions, which are readily evaluated by comparative CPMAS and DDMAS studies, is... 

Lomakin, A., Chung, D. S., Benedek, G. B., Kirschner, D. A., and Teplow, D. B. (1996). On the nucleation and growth of amyloid beta-protein fibrils Detection of nuclei and quantitation of rate constants. Proc. Natl. Acad. Sci. USA 93, 1125-1129. 

Lundmark, K., Westermark, G. T., Olsen, A., and Westermark, P. (2005). Protein fibrils in nature can enhance amyloid protein A amyloidosis in mice Cross-seeding as a disease mechanism. Proc. Natl. Acad. Sci. USA 102, 6098-6102. 

Bousset, L., Thomson, N. H., Radford, S. E., and Melki, R. (2002). The yeast prion Ure2p retains its native a-helical conformation upon assembly into protein fibrils in vitro. EMBOJ. 21, 2903-2911. 

Fay, N., Inoue, Y., Bousset, L., Taguchi, H., and Melki, R. (2003). Assembly of the yeast prion Ure2p into protein fibrils. Thermodynamic and kinetic characterization. /. Biol. Chem. 278, 30199-30205. 

CYP cytochrome P450. cytolytic causing lysis of cells, cytoskeletal relating to the cytoskeleton. cytoskeleton network of protein fibrils within cells, cytotropic a class of antibodies that attach to tissue cells. 

Tycko, R. 2001. Biomolecular solid state NMR Advances in structural methodology and applications to peptide and protein fibrils. Anna. Rev. Phys. Chem. 52 575-606. 

Ethanol and methanol have been used to swell other types of keratinized protein without loss of the a-helieal structure in the presence or after removal of the alcohols (46). Polar lipids such as the ceramides or sphingolipids are soluble in methanol (47). Therefore, extensive extraction periods in methanol could have provided sufficient time to swell the keratinized protein and allow the highly polar lipids entrapped within the protein fibrils to diffuse from the stratum corneum sheet. The resultant protein residue sheets retained the a-keratin conformation throughout the extensive extraction process. 

Natural extracellular matrices in vivo consist of various protein fibrils and fibers, interwoven within a hydrated network of glycosaminoglycan chains and may require less than 1% solid materials to form mechanically robust... 

UV-Exposed Prion Protein Fibrils Show Altered Fibril Morphology... 

Two unfortunate names that can easily lead to confusion have been given to the in-pathway conformations protofibrils and protofilaments. Protofibrils are, similar to oligomers, mostly unstructured but linear (31). However, in most cases the term protofibrils is used interchangeably with the term oligomer. The name protofilaments refers to linear aggregates with P-sheet structure that have a diameter of 3nm and are usually 50-100 nm in length. Mature, elongated protofilaments, also called filaments, intertwine to form protein fibrils. Fibrils... 

The wide angle x-ray diffraction pattern of undeformed corneum exhibits diffuse halos at 4.6 A and 9.8 A common to proteins (Figure 4). The lack of the 5.1-A reflection characteristic of alpha-keratin structures in undeformed comeum suggests that the protein is considerably less oriented and perhaps of a lower alpha content than wool. This is supported by the fact that the 5.1-A reflection begins to appear in samples of comeum which were hydrated and stretched to 100% or more (Figure 6) and allowed to dry in the extended state. The increased orientation of the lipid reflections in the stretched sample demonstrates further their association with the orienting protein fibrils. 

Reviews on subjects of biological interest have included structural character-izaton of peptides and protein fibrils and membrane-bound peptides and proteins using advanced solid-state NMR techniques, single N labelled polypeptides reconstructed into oriented membranes by static or H, N and MAS solid-state NMR techniques, new physicochemical approaches based on recently developed DRAWS pulse sequence for examination of fibrils... 

Smirnovas V, Kim J, Lu X et al (2009) Distinct structures of scrapie prion protein (PrPSc)-seeded versus spontaneous recombinant prion protein fibrils revealed by hydrogen/deuterium exchange. J Biol Chem 284 24233-24241... 

Present study deals with specific aspects of development of hybrid proteins capable to create p-sheeted protein fibrils and integration of the fibrils with solid surfaces. Our study aims to define the most essential conditions and parameters on which the arrangement of the complex object on the solids depends. Morphology,... 

Zanuy, D., Nusinov, R., Aleman, C. From peptide-based material science to protein fibrils discipline convergence in nanobiology, Phys. Biology 3. (2006) S80-S90. 

Fay N, Inoue Y, Bousset L, Taguchi H, Melki R (2003) Assembly of the yeast prion Ure2p into protein fibrils. 

Fezoui Y, Teplow DB (2002) Kinetic smdies of amyloid beta-protein fibril assembly. Differential effects of alpha-helix stabilization. J Biol Chem 277 36948—36954 Fezoui Y, Hartley DM, Walsh DM, Selkoe DJ, Osterhout JJ, Teplow DB (2000) A de novo designed helix-turn-helix peptide forms nontoxic amyloid fibrils. Nat Struct Biol 7 1095-1099 Figueroa KP, Pulst SM (2003) Identification and expression of the gene for human ataxin-2-related protein on chromosome 16. Exp Neurol 184 669-678... 

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