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Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin
Published on: March 10, 2021
A recurrent D-strand association interface is observed in β-2 microglobulin oligomers
Matteo Colombo1, Matteo de Rosa, Vittorio Bellotti
1Dipartimento di Scienze Biomolecolari e Biotecnologie and CIMAINA, Università di Milano, Italy.
The FEBS Journal
|February 1, 2012
Summary
Beta-2 microglobulin (β2m) oligomerization, crucial for dialysis-related amyloidosis, involves specific D-strand interactions. Impairing these interactions prevents amyloid formation, offering insights into disease mechanisms.
Area of Science:
- Biochemistry
- Structural Biology
- Protein Misfolding Diseases
Background:
- Beta-2 microglobulin (β2m) is implicated in dialysis-related amyloidosis.
- Early stages of amyloid fibril formation involve β2m oligomerization, but structural details remain unclear.
Purpose of the Study:
- To characterize protein-protein interactions in β2m oligomer formation.
- To investigate the role of specific interfaces in amyloidogenicity.
Main Methods:
- Preparation of disulfide-linked β2m homodimers (DIMC20, DIMC50, DIMC60).
- Assessment of amyloid propensity, solution oligomerization state, and crystallogenesis.
- X-ray crystallography to determine the structure of tetrameric assemblies.
Main Results:
- DIMC20 and DIMC50 formed tetramers via conserved D-strand interactions, yielding crystals and amyloid fibrils.
- DIMC60, with an impaired D-strand interface, remained dimeric, did not crystallize, and was not amyloidogenic.
- DIMC20 and DIMC50 induced amyloid formation in wild-type β2m.
Conclusions:
- The noncovalent D-strand association is critical for β2m tetramer formation and subsequent amyloidogenicity.
- Disruption of the D-strand interface by disulfide bonds inhibits oligomerization and amyloid formation.
- Understanding these interactions provides a basis for therapeutic strategies against β2m amyloidosis.
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