Cyclic N-terminal loop of amylin forms non amyloid fibers

Stephanie M. Cope, Sandip Shinde, Robert B. Best, Giovanna Ghirlanda, Sara Vaiana

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


We report for the first time, to our knowledge, that the N-terminal loop (N-loop) of amylin (islet amyloid polypeptide (IAPP) residues 1-8) forms extremely long and stable non-β-sheet fibers in solution under the same conditions in which human amylin (hIAPP) forms amyloid fibers. This observation applies to the cyclic, oxidized form of the N-loop but not to the linear, reduced form, which does not form fibers. Our findings indicate a potential role of direct N-loop-N-loop interactions in hIAPP aggregation, which has not been previously explored, with important implications for the mechanism of hIAPP amyloid fiber formation, the inhibitory action of IAPP variants, and the competition between ordered and disordered aggregation in peptides of the calcitonin peptide family.

Original languageEnglish (US)
Pages (from-to)1661-1669
Number of pages9
JournalBiophysical journal
Issue number7
StatePublished - Oct 1 2013

ASJC Scopus subject areas

  • Biophysics


Dive into the research topics of 'Cyclic N-terminal loop of amylin forms non amyloid fibers'. Together they form a unique fingerprint.

Cite this