Aggregation and fibrillation

It is not clear in this case whether insulin had formed aggregates and fibrils due to the high temperature or if the action of counter-regulatory hormones induced by hyperthermia was increased, or both. 

Swietnicki W, Morillas M, Chen SG et al (2000) Aggregation and fibrillization of the recombinant human prion protein huPrP90—231. Biochemistry 39 424-431... 

Protein Aggregation and Fibril Formation Membrane Protein Structure and Assemblies... 

Xiong LW, Raymond LD, Hayes SF, Raymond GJ, Caughey B. Conformational change, aggregation and fibril formation induced by detergent treatments of cellular prion protein. / Neurochem. 2001 79(3) 669-678. 

The twist of these aggregates determines the resulting structure. When ribbons stack into fibrils, and fibrils into fibres, packing considerations cause these twisted aggregates to bend and modify their twist with an elastic energy penalty8eiast- For fibrils, it can be shown that the afibrii per peptide in a fibril is ... 

In any case, through the propensity and specificity for aggregation (e.g., by jS-sheet formation in amyloids), proteins, silk, or otherwise, they will precipitate and form disordered aggregates or fibrils under the appropriate conditions (whether in vivo or in vitro Dobson, 1992 Fandrich et al., 2001 Uversky and Fink, 2004). 

Fibrils aggregate and cross-link to form collagen fibers. 

Hu, J., Igarashi, A., Kamata, M., Nakagawa, H. (2001) Angiotensin-converting enzyme degrades Alzheimer amyloid [3-peptide (A[3) retards A[3 aggregation, deposition, fibril formation and inhibits cytotoxicity. J. Biol. Chem., 276, 47863 7868. 

Whiskers are synthetic crystalline fibers of variable size, but with diameters of usually less than 25 microns. An upper limit in diameter exists because the physical and chemical properties approach those of the bulk material as the diameter of fibrous sample increases. Since the purpose of synthesis is to take advantage of some characteristic property of the material in fibrous form, such as enhanced strength for small volume, the optimum material has a small diameter. For similar reasons the aspect ratio of useful whiskers is often well over 100. Whiskers can be single crystals, but many are polycrystalline aggregates of fibrils with preferred orientations. The compositions and crystal structures of the compounds synthesized as crystalline fibers also have the broadest possible variety (Brenner, 1958). 

Trotter, J. A., Lyons-Levy, G., Luna, D., Koob, T. J., Keene, D. R., and Atkinson, M. A. L. (1996). Stiparin A glycoprotein from sea cucumber dermis that aggregates collagen fibrils. Matrix Biol. 15, 99-110. 

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