9HX4 | pdb_00009hx4

Amyloid fibril of apolipoprotein A-IV

• PDB DOI: https://doi.org/10.2210/pdb9HX4/pdb
• EM Map EMD-52457: EMDB EMDataResource

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


• Deposited: 2025-01-06 Released: 2025-11-05 
• Deposition Author(s): Aibara, S., Kassner, A., Wong, E., Klingel, K., Papworth, M., Althage, M., Wang, Q.D., Correia, C., Milting, H., Oliveira, T.M.
• Funding Organization(s): Not funded

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.30 Å
• Aggregation State: HELICAL ARRAY 
• Reconstruction Method: HELICAL 

Literature

Apolipoprotein A-IV fibrils: structural diagnosis of mixed cardiac amyloidosis.

Aibara, S., Kassner, A., Wong, E., Klingel, K., Papworth, M., Althage, M., Wang, Q.D., Correia, C., Milting, H., de Oliveira, T.M.

(2025) Nat Commun 16: 9276-9276

• PubMed: 41115976 
• DOI: https://doi.org/10.1038/s41467-025-64902-0
• Primary Citation Related Structures: 
  9HX3, 9HX4


• PubMed Abstract: 
  

  Cardiac amyloidosis (CA) occurs when misfolded proteins deposit as fibrils in the extracellular space of the heart. The fibrillogenic properties of apolipoprotein A-IV (ApoAIV) have been histologically observed and associated with CA pathogenesis. We report the structure of an ApoAIV amyloid from a patient's heart, which coexist amongst transthyretin (TTR) amyloids. These cases of undetected mixed CA highlight the importance of developing broad-spectrum anti-amyloid treatments to improve outcomes in patients.

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Organizational Affiliation: 
• Protein Sciences, Structure, and Biophysics, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK.
Heart and Diabetes Center NRW, Bad Oeynhausen, Germany.
Biologics Engineering, R&D, AstraZeneca, Cambridge, UK.
Cardiopathology, Institute for Pathology, University Hospital Tübingen,Liebermeisterstr. 8, Tübingen, Germany.
Translational Science and Experimental Medicine, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden.
Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden.
Heart and Diabetes Center NRW, Bad Oeynhausen, Germany. [e-mail].
Protein Sciences, Structure, and Biophysics, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK. [e-mail].

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 10-mer - A10 

Biological assembly 1 assigned by authors and generated by (software)

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 454.34 kDa 
• Atom Count: 4,840 
• Modeled Residue Count: 610 
• Deposited Residue Count: 3,960 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Apolipoprotein A-IV	A [auth F], B [auth E], C [auth B], D [auth A], E [auth C], F [auth D], G, H, I, J	396	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P06727 (Homo sapiens) Explore P06727  Go to UniProtKB:  P06727
PHAROS:  P06727 GTEx:  ENSG00000110244

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.30 Å
• Aggregation State: HELICAL ARRAY 
• Reconstruction Method: HELICAL 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.21.1_5286:

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2025-11-05 
Deposition Author(s): Aibara, S., Kassner, A., Wong, E., Klingel, K., Papworth, M., Althage, M., Wang, Q.D., Correia, C., Milting, H., Oliveira, T.M.

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Funding Organization	Location	Grant Number
Not funded		--

Revision History  

• Version 1.0: 2025-11-05
  Type: Initial release