Download MendeleyAtomic resolution structure of full-length human insulin fibrils.
Suladze, S., Sarkar, R., Rodina, N., Bokvist, K., Krewinkel, M., Scheps, D., Nagel, N., Bardiaux, B., Reif, B.(2024) Proc Natl Acad Sci U S A 121: e2401458121-e2401458121
- PubMed: 38809711
- DOI: https://doi.org/10.1073/pnas.2401458121
- Primary Citation of Related Structures:
8RVT - PubMed Abstract:
Patients with type 1 diabetes mellitus who are dependent on an external supply of insulin develop insulin-derived amyloidosis at the sites of insulin injection. A major component of these plaques is identified as full-length insulin consisting of the two chains A and B. While there have been several reports that characterize insulin misfolding and the biophysical properties of the fibrils, atomic-level information on the insulin fibril architecture remains elusive. We present here an atomic resolution structure of a monomorphic insulin amyloid fibril that has been determined using magic angle spinning solid-state NMR spectroscopy. The structure of the insulin monomer yields a U-shaped fold in which the two chains A and B are arranged in parallel to each other and are oriented perpendicular to the fibril axis. Each chain contains two β-strands. We identify two hydrophobic clusters that together with the three preserved disulfide bridges define the amyloid core structure. The surface of the monomeric amyloid unit cell is hydrophobic implicating a potential dimerization and oligomerization interface for the assembly of several protofilaments in the mature fibril. The structure provides a starting point for the development of drugs that bind to the fibril surface and disrupt secondary nucleation as well as for other therapeutic approaches to attenuate insulin aggregation.
Organizational Affiliation:
Bavarian Nuclear Magnetic Resonance Center at the Department of Biosciences, School of Natural Sciences, Technische Universität München, Garching 85747, Germany.
