9JHG

Cryo-em structure of beta-LG fibril

Summary for 9JHG

• Entry DOI: 10.2210/pdb9jhg/pdb
• EMDB information: 61481
• Descriptor: Beta-lactoglobulin fibrils (1 entity in total)
• Functional Keywords: protein fribril, nanomaterials, protein fibril
• Biological source: Bos taurus (domestic cattle)
• Total number of polymer chains: 6
• Total formula weight: 20646.40

Authors

Xu, Y.Y.,Liu, C. (deposition date: 2024-09-09, release date: 2025-09-03)

Primary citation

Xu, Y.,Li, D.,Zhang, Y.,Zhao, Q.,Sun, B.,Liu, C.,Li, D.,Dai, B.
beta-Lactoglobulin Forms a Conserved Fibril Core That Assembles into Diverse Fibril Polymorphs.
Nano Lett., 25:3653-3661, 2025

PubMed Abstract: The β-lactoglobulin (β-LG) protein, sourced from dietary products, is notable for forming amyloid fibrils, which are increasingly recognized as valuable protein-based nanomaterials due to their superior cytocompatibility, chemical resilience, and mechanical characteristics. However, the precise atomic details of β-LG's fibril assembly are not understood. In this study, we utilized cryo-electron microscopy to elucidate the composition and architecture of β-LG fibrils. We discovered that the β-LG fibril was rapidly assembled after a short time incubation. Remarkably, these fibril cores were composed of the first 32 residues, forming four β-strands that adopted a serpentine arrangement into a single protofilament. This protofilament core's stability was reinforced by hydrophobic interactions. Two identical protofilaments then align to form four distinct structural polymorphs through unique interfacial configurations, which were stabilized by hydrophilic interactions, hydrogen bonding, and electrostatic forces. Our findings provide a structural framework for understanding β-LG fibril formation and pave the way for designing innovative β-LG-based nanomaterials.

PubMed: 39992798
DOI: 10.1021/acs.nanolett.5c00137

Experimental method

ELECTRON MICROSCOPY (3.38 Å)