|Title||Fibril formation and toxicity of the non-amyloidogenic rat amylin peptide|
|Authors||Milton, N.G.N. and Harris, J.R.|
Full-length native rat amylin 1-37 has previously been widely shown to be unable to form fibrils and to lack the toxicity of the human amylin form leading to its use as a non-amyloidogenic control peptide. A recent study has suggested that rat amylin 1-37 forms amyloidogenic β-sheet structures in the presence of the human amylin form and suggested that this property could promote toxicity. Using TEM analysis we show here fibril formation by synthetic rat amylin 1-37 and 8-37 peptides when the lyophilized HPLC purified peptides are initially dissolved in 20 mM Tris-HCl. Dissolution of synthetic rat amylin 1-37 and 8-37 peptides in H(2)O or phosphate buffered saline failed to produce fibrils. Addition of 20 mM Tris-HCl to synthetic rat amylin 1-37 and 8-37 peptides initially dissolved in H(2)O also failed to induce fibril formation. The rat amylin fibrils have a uniform structure and bind Congo red suggesting that they are amyloid fibrils. The rat amylin fibrils also bind catalase, which could be inhibited by Amyloid-β 31-35 and a catalase amyloid-β binding domain-like peptide (R9). The rat amylin 1-37 and 8-37 fibrils are toxic in both human pancreatic islet and neuronal cell culture systems. The toxicity of rat amylin fibrils can be inhibited by an amylin receptor antagonist (AC187) and a caspase inhibitor (zVAD-fmk) in a similar manner to previous observations for human amylin toxicity. Chemically induced rat amylin fibril formation of uniform structured fibrils provides a potentially novel anti-amyloid drug discovery tool.
|Journal citation||44, pp. 246-253|
|Digital Object Identifier (DOI)||doi:10.1016/j.micron.2012.07.001|