Detection and quantitation of beta-2-microglobulin glycosylated end products in human serum by matrix-assisted laser desorption/ionization mass spectrometry.
beta-2-Microglobulin (beta 2M) is a major protein component found in the amyloid deposits of dialysis-related amyloidosis (DRA) patients. Evidence has been shown that the advanced glycosylated end-products (AGEs) of beta 2M present in sera were related to DRA. We demonstrated that matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a useful tool to investigate the nature of glycosylation of beta 2M and detection of beta 2M or beta 2M-AGEs in human serum. The high-mass end of beta 2M-AGE distribution was found to extend to the neighborhood of 12,868 Da, corresponding to condensations with seven glucose molecules. We also have shown that both beta 2M and beta 2M-AGEs can be detected at low picomole levels directly in bovine serum. Based on these findings, the sera of DRA patients were studied to determine whether beta 2M-AGEs can be detected by MALDI-MS. In an attempt to investigate the possibility of quantitation with MALDI, human sera samples with different concentrations of beta 2M-AGE were examined. We were able to correlate the concentration of beta 2M-AGE with the number of detected AGE products, pointing to the feasibility of MALDI as a quantitative tool.
Department of Chemistry, George Washington University, Washington, D.C. 20052, USA.
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Tang
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M
Sadeghi
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Z
Olumee
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Vertes
J A
JA
Braatz
L K
LK
McIlwain
P A
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Dreifuss
D000818:Animals; D002417:Cattle; D017127:Glycation End Products, Advanced / Q000097:blood*; D006801:Humans; D006435:Renal Dialysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D001613:beta 2-Microglobulin / Q000378:metabolism*
D017127:Glycation End Products, Advanced; D001613:beta 2-Microglobulin