title: The emergence of superstructural order in insulin amyloid fibrils upon multiple rounds of self-seeding.
abstract: Typically, elongation of an amyloid fibril entails passing conformational details of the mother seed to daughter generations of fibrils with high fidelity. There are, however, several factors that can potentially prevent such transgenerational structural imprinting from perpetuating, for example heterogeneity of mother seeds or so-called conformational switching. Here, we examine phenotypic persistence of bovine insulin amyloid ([BI]) upon multiple rounds of self-seeding under quiescent conditions. According to infrared spectroscopy, with the following passages of homologous seeding, daughter fibrils gradually depart from the mother seed's spectral characteristics. We note that this transgenerational structural drift in [BI] amyloid leads toward fibrils with infrared, chiroptical, and morphological traits similar to those of the superstructural variant of fibrils which normally forms upon strong agitation of insulin solutions. However, in contrast to agitation-induced insulin amyloid, the superstructural assemblies of daughter fibrils isolated through self-seeding are sonication-resistant. Our results suggest that formation of single amyloid fibrils is not a dead-end of the amyloidogenic self-assembly. Instead, the process appears to continue toward the self-assembly of higher-order structures although on longer time-scales. From this perspective, the fast agitation-induced aggregation of insulin appears to be a shortcut to amyloid superstructures whose formation under quiescent conditions is slow.
authors: Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland.|Institute of Biotechnology and Antibiotics, Staroscinska 5, 02-516 Warsaw, Poland.
authors: Weronika
authors: W
authors: Surmacz-Chwedoruk
authors: Department of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
authors: Viktoria
authors: V
authors: Babenko
authors: Department of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
authors: Robert
authors: R
authors: Dec
authors: Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
authors: Piotr
authors: P
authors: Szymczak
authors: Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland.|Department of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
authors: Wojciech
authors: W
authors: Dzwolak
mesh_terms: D000682:Amyloid / Q000737:chemistry* / Q000378:metabolism; D002942:Circular Dichroism; D007328:Insulin / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D018625:Microscopy, Atomic Force; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D000682:Amyloid; D007328:Insulin