naa a22 4500 510738249 CHVBK 20180411083018.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s12127-012-0115-z doi (NATIONALLICENCE)springer-10.1007/s12127-012-0115-z Monitoring oligomer formation from self-aggregating amylin peptides using ESI-IMS-MS [Elektronische Daten] [Lydia Young, Hlengisizwe Ndlovu, Tom Knapman, Sarah Harris, Sheena Radford, Alison Ashcroft] Amyloid diseases are a serious cause for concern world-wide. To understand the mechanism of formation of the fibrillar structures associated with such disorders, it is necessary to study the progression from soluble protein or peptide monomer through an array of oligomers to the final, insoluble, fibrils. The protein IAPP is found in vivo in the form of insoluble amyloid deposits in the pancreatic islets of diabetes type II sufferers. Here, we have studied the in vitro self-aggregation of three fibril-forming peptides from the amyloidogenic core of IAPP. Using electrospray ionization—mass spectrometry coupled with ion mobility spectrometry, the mass and cross-sectional area of each oligomer present in the heterogeneous assembly mixtures can be determined individually in a single, rapid experiment over time. For the three peptides studied, oligomers ≤20-mer were characterized. Conversely, no oligomers higher than a dimer were detected for a non-assembling peptide control. The rate in which the cross-sectional area of the oligomers increases with increasing number of peptide sub-units indicates that assembly for the amyloid-forming peptides proceeds in a linear fashion until an oligomer of a certain size is attained. After this, a step increase in cross-sectional area occurs for the next higher-order oligomer. This behaviour can be explained by molecular modelling of singly, doubly, triply and quadruply stacked β-stranded structures. Using one peptide as an example, the cross-sectional areas of the lower order oligomers (dimer to pentamer) were found to be consistent with a single β-sheet model, whereas the higher order oligomers were consistent with double-stranded (hexamer to decamer oligomers), triply-stranded (11-mers to 15-mers) and quadruply-stranded (16-mers to 20-mers) β-sheet models. Springer-Verlag Berlin Heidelberg, 2013 Ion mobility spectrometry-mass spectrometry nationallicence Islet amyloid polypeptide nationallicence Amyloid nationallicence Fibril nationallicence Molecular modelling nationallicence Young Lydia Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut Ndlovu Hlengisizwe Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut Knapman Tom Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut Harris Sarah Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut Radford Sheena Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut Ashcroft Alison Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut International Journal for Ion Mobility Spectrometry Springer-Verlag 16/1(2013-03-01), 29-39 1435-6163 16:1<29 2013 16 12127 https://doi.org/10.1007/s12127-012-0115-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12127-012-0115-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Young Lydia Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut NATIONALLICENCE 700 1- Ndlovu Hlengisizwe Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut NATIONALLICENCE 700 1- Knapman Tom Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut NATIONALLICENCE 700 1- Harris Sarah Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut NATIONALLICENCE 700 1- Radford Sheena Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut NATIONALLICENCE 700 1- Ashcroft Alison Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK aut NATIONALLICENCE 773 0- International Journal for Ion Mobility Spectrometry Springer-Verlag 16/1(2013-03-01), 29-39 1435-6163 16:1<29 2013 16 12127 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer