9ULZ | pdb_00009ulz

Cryo-EM structure of hIAPP fibrils extracted from a donor with T2D and pancreatic cancer

• PDB DOI: https://doi.org/10.2210/pdb9ULZ/pdb
• EM Map EMD-64268: EMDB EMDataResource

• Classification: PROTEIN FIBRIL
• Organism(s): Homo sapiens
• Mutation(s): No 


• Deposited: 2025-04-21 Released: 2026-01-14 
• Deposition Author(s): Cao, Q., Liu, W., Han, J.
• Funding Organization(s): National Natural Science Foundation of China (NSFC)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: FILAMENT 
• Reconstruction Method: HELICAL 

Literature

Structure of pancreatic hIAPP fibrils derived from patients with type 2 diabetes.

Liu, W., Han, J., Gong, W., Zhang, F., Cao, Q.

(2026) Cell 189: 1201

• PubMed: 41483806 
• DOI: https://doi.org/10.1016/j.cell.2025.12.001
• Primary Citation Related Structures: 
  9ULZ


• PubMed Abstract: 
  

  Type 2 diabetes (T2D) impacts the quality of life and lifespan of nearly 10% of the global population. Human islet amyloid polypeptide (hIAPP) constitutes a major component of islet amyloid deposition in patients with T2D, with hIAPP fibrils believed to play a key role in the pathogenesis of T2D. In this study, we determined the cryo-electron microscopy (cryo-EM) structure of hIAPP fibrils extracted from surgically resected pancreases of three donors with T2D. These fibrils exhibit a uniform morphology, comprising two symmetrical protofilaments encompassing residues 2-37 of hIAPP and adopting an Ω-shaped fold. The structure of pancreatic hIAPP fibrils differs from that of fibrils formed in vitro. Additional densities were observed in the pancreatic hIAPP fibrils, suggesting ligand binding that may play significant roles in the pathogenesis of T2D. Collectively, our study presents the atomic structure of pathological hIAPP fibrils, contributing to the therapeutic and mechanistic exploration of T2D.

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Organizational Affiliation: 
• Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China.
Department of General Surgery, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Research Center of Biliary Tract Disease, Shanghai 200092, China.
Department of General Surgery, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Research Center of Biliary Tract Disease, Shanghai 200092, China. Electronic address: [e-mail].
Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China. Electronic address: [e-mail].

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 12-mer - A12 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 46.91 kDa 
• Atom Count: 3,168 
• Modeled Residue Count: 432 
• Deposited Residue Count: 444 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Islet amyloid polypeptide	A, B, C, D, E, F, G, H, I, J, K, L	37	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P10997 (Homo sapiens) Explore P10997  Go to UniProtKB:  P10997
PHAROS:  P10997 GTEx:  ENSG00000121351

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: FILAMENT 
• Reconstruction Method: HELICAL 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.20.1_4487:

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-01-14 
Deposition Author(s): Cao, Q., Liu, W., Han, J.

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Funding Organization	Location	Grant Number
National Natural Science Foundation of China (NSFC)	China	--

Revision History  

• Version 1.0: 2026-01-14
  Type: Initial release
  
• Version 1.1: 2026-03-11
  Changes: Data collection, Database references