2YXF

The high resolution crystal structure of beta2-microglobulin under physiological conditions

Summary for 2YXF

• Entry DOI: 10.2210/pdb2yxf/pdb
• Related: 2D4F
• Descriptor: Beta-2-microglobulin (2 entities in total)
• Functional Keywords: immune system
• Biological source: Homo sapiens (human)
• Cellular location: Secreted: P61769
• Total number of polymer chains: 1
• Total formula weight: 11879.36

Authors

Iwata, K.,Matsuura, T.,Nakagawa, A.,Goto, Y. (deposition date: 2007-04-26, release date: 2007-10-30, Last modification date: 2024-10-23)

Primary citation

Iwata, K.,Matsuura, T.,Sakurai, K.,Nakagawa, A.,Goto, Y.
High-resolution Crystal Structure of {beta}2-Microglobulin Formed at pH 7.0
J.Biochem.(Tokyo), 142:413-419, 2007

PubMed Abstract: beta(2)-Microglobulin (beta2-m), a light chain of the major histocompatibility complex class I, forms amyloid fibrils in patients undergoing long-term haemodialysis, causing dialysis-related amyloidosis. Based on a comparison of the X-ray structure obtained at pH 5.7 and that of beta2-m in the histocompatibility complex, it has been proposed that the continuous D-strand observed in the crystal structure at pH 5.7 increases the propensity of beta2-m to self-associate via edge-to-edge interactions, thus initiating the formation of fibrils. To obtain further insight into the mechanism by which amyloid fibrils form, we determined the crystal structure of beta2-m at pH 7.0 at a resolution of up to 1.13 A. The crystal structure at pH 7.0 was basically the same as that at pH 5.6, suggesting that the conversion of the beta-bulge in strand D into a contiguous beta-strand is not unique to the crystals formed under slightly acidic conditions. In other words, although the formation of beta2-m fibrils was enhanced under acidic conditions, it remains unknown if it is related to the increased propensity for the disappearance of the beta-bulge in strand D. We consider that the enhanced fibrillation is more directly coupled with the decreased stability leading to the increased propensity of exposing amyloidogenic regions.

PubMed: 17646174
DOI: 10.1093/jb/mvm148

Experimental method

X-RAY DIFFRACTION (1.13 Å)