A membrane-bound antiparallel dimer of rat islet amyloid polypeptide.

A Membrane-bound Antiparallel Dimer of Rat Islet Amyloid Polypeptide IAPP, an amyloidogenic peptide linked to type 2 diabetes, forms a heterogeneous mixture of membrane-bound oligomers implicated in cytotoxicity and fibril formation. Structural characterization of these species has been a long-standing problem. Here, we examine the structure of a previously unrecognized antiparallel dimer of rat IAPP bound to anionic membrane Nanodiscs, using a novel combination of single-pair FRET and Rosetta model refinement.