Insulin forms amyloid in a strain-dependent manner: an FT-IR spectroscopic study.
The presence of 20% (v/v) ethanol triggers growth of insulin amyloid with distinct infrared spectroscopic features, compared with the fibrils obtained under ambient conditions. Here we report that the two insulin amyloid types behave in the prion strain-like manner regarding seeding specificity and ability of the self-propagating conformational template to overrule unfavorable environmental factors and maintain the initial folding pattern. The type of the original seed has been shown to prevail over cosolvent effects and determines spectral position and width of the amide I' infrared band of the heterogeneously seeded amyloid. These findings imply that "strains" may be a common generic trait of amyloids.
Dzwolak
Wojciech
W
High Pressure Research Center, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland. wdzwolak@unipress.waw.pl
Smirnovas
Vytautas
V
Jansen
Ralf
R
Winter
Roland
R
D000818:Animals; D002417:Cattle; D007328:Insulin / Q000737:chemistry*; D007700:Kinetics; D046912:Multiprotein Complexes / Q000737:chemistry*; D011328:Prions / Q000737:chemistry; D011487:Protein Conformation; D017510:Protein Folding; D013055:Spectrophotometry, Infrared
D007328:Insulin; D046912:Multiprotein Complexes; D011328:Prions