Prion-related peptides

X-ray diffraction patterns from the assemblies formed by several prion-related peptides have been analyzed (Fig. 6), including SHal06-122 (KTNMKHMAGAAAAGAW) and HI (i.e., SHal09-122, MKHMAGAAAA-GAW) (Inouye et al, 2000 Nguyen et al., 1995), and the palindromic A8A... 

Inouye, H., and Kirschner, D. A. (2003). X-ray fibre diffraction analysis of assemblies formed by prion-related peptides Polymorphism of the heterodimer interface between PrPC and PrPSc. Fibre Diffract. Rev. 11, 102-112. 

Forloni, G., Tagliavini, F., Bugiani, O. and Salmona, M. (1996) Amyloid in Alzheimer s disease and prion-related encephalopathies studies with synthetic peptides. Prog Neurobiol, 49, 287-315. 

TI Amyloid in Alzheimer s disease and prion-related encephalopathies Studies with synthetic peptides... 

Recently, a seven-residue peptide from the Sup35p prion domain has been analyzed by X-ray crystallography (Nelson et al., 2005). Although there is, in general, little reason to suppose that a short peptide will assume the same structure in a crystal as it will in the context of a folded protein containing it, these crystals seem to be related to amyloid fibrils of the same... 

Situations which can change the conformation of prion proteins are related to the activation of microglial cells, releasing proinflammatory cytokines and reactive oxygen species. Hiis elevated oxidative stress may somehow alter the conformation of the protein. Experiments with synthetic human prion peptides (PrP 106-126, PrP 127-147) revealed that the peptide structure is the relevant toxic factor for neuronal cells. PC 12 cells in vitro died... 

The competitive assay fonnat [82-84] (Fig. 8) performed better than noncompetitive assays [85] for the determination of prion protein (PrP) in brain samples. In the competitive assay, antigen in the sample competes in solution, prior to injection onto the CE column, with a labeled peptide of the PrP to bind to an antibody directed against this peptide. The presence of antigen in the sample increased the size of the CZE peak corresponding to free labeled peptide and decreased that of peptide bound to antibody. Probably, in this case, the higher performance of the competitive mode was not related to the format of the assay but to the successive improvements in sample and antibody purification, in the process of peptide labeling, and in the carefiil choice of the separation buffer carried out in this format. 

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