Lysine 58‐cleaved β2‐microglobulin is not detectable by 2D electrophoresis in ex vivo amyloid fibrils of two patients affected by dialysis‐related amyloidosis
- 1 February 2007
- journal article
- Published by Wiley in Protein Science
- Vol. 16 (2), 343-349
- https://doi.org/10.1110/ps.062563507
Abstract
The lysine 58 cleaved and truncated variant of beta(2)-microglobulin (DeltaK58-beta2m) is conformationally unstable and present in the circulation of a large percentage of patients on chronic hemodialysis, suggesting that it could play a role in the beta2-microglobulin (beta2m) amyloid fibrillogenesis associated with dialysis-related amyloidosis (DRA). However, it has yet to be detected in the amyloid deposits of such patients. Here, we extracted amyloid fibrils, without denaturation or additional purification, from different amyloidotic tissues of two unrelated individuals suffering from DRA, and characterized them by high-sensitivity bidimensional gel electrophoresis (2D-PAGE), immunoblotting, MALDI time-of-flight mass spectrometry, and protein sequencing. To confirm whether or not this species could be identified by our proteomic approaches, we mapped its location in 2D-PAGE, in mixtures of pure DeltaK58-beta2m, and extracts of amyloid fibrils from patients, to a discrete region of the gel distinct from other isoforms of beta2m. Using this approach, the two known principal isoforms found in beta2m amyloid were identified, namely, the full-length protein and the truncated species lacking six N-terminal amino acid residues (DeltaN6-beta2m). In contrast, we found no evidence for the presence of DeltaK58-beta2m.Keywords
This publication has 27 references indexed in Scilit:
- Variants of β2-microglobulin cleaved at lysine-58 retain the main conformational features of the native protein but are more conformationally heterogeneous and unstable at physiological temperatureThe FEBS Journal, 2006
- Quantification of Cleaved β2-Microglobulin in Serum from Patients Undergoing Chronic HemodialysisClinical Chemistry, 2005
- Unfolding, Aggregation, and Seeded Amyloid Formation of Lysine-58-Cleaved β2-MicroglobulinBiochemistry, 2005
- Conformational Intermediate of the Amyloidogenic Protein β2-Microglobulin at Neutral pHPublished by Elsevier ,2001
- Use of Anti‐(β2 Microglobulin) mAb to Study Formation of Amyloid FibrilsEuropean Journal of Biochemistry, 1997
- Beta 2 microglobulin isoforms in healthy individuals and in amyloid depositsKidney International, 1995
- Limited proteolysis of β2‐microglobulin at Lys‐58 by complement component C1sEuropean Journal of Biochemistry, 1990
- Purification and biochemical characterization of the complete structure of a proteolytically modified β‐2‐microglobulin with biological activityEuropean Journal of Biochemistry, 1987
- β2-Microglobulin, Different Fragments and Polymers thereof in Synovial Amyloid in Long-Term HemodialysisBiological Chemistry Hoppe-Seyler, 1987
- A new form of amyloid protein associated with chronic hemodialysis was identified as β2-microglobulinBiochemical and Biophysical Research Communications, 1985