Molecular heterogeneity of amyloid beta2-microglobulin and modification with advanced glycation end products.
By using liquid chromatography-electrospray ionization mass spectrometry, Western blotting and N-terminal amino acid sequence analysis, we characterized the molecular heterogeneity and advanced glycation end product (AGE) modification of beta2-microglobulin (beta2m) extracted from the amyloid tissue of a hemodialysis patient. Amyloid beta2m was composed of full-length beta2m, truncated beta2m and dimer beta2m. Truncated beta2m and dimer beta2m were modified with AGEs such as imidazolone and N(e)-(carboxymethyl)lysine, and showed fluorescence characteristic of AGE. Truncated beta2m species were formed by cleavage between amino acid residues of Pro6/Ile7, Gln/Val9 and Val9/Tyr10. Heterogeneous dimer beta2m species showed the molecular masses of 22,591 and 22 675, which resulted from cross-linking between truncated beta2m.
Mironova
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R
Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia.
Niwa
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T
D000596:Amino Acids / Q000737:chemistry; D000682:Amyloid / Q000737:chemistry* / Q000378:metabolism; D000686:Amyloidosis / Q000209:etiology / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D017127:Glycation End Products, Advanced / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006435:Renal Dialysis / Q000009:adverse effects; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization; D001613:beta 2-Microglobulin / Q000737:chemistry* / Q000378:metabolism
D000596:Amino Acids; D000682:Amyloid; D017127:Glycation End Products, Advanced; D001613:beta 2-Microglobulin