Advanced glycation end products of beta₂-microglobulin in uremic patients as determined by high resolution mass spectrometry

详细信息    查看全文

• 作者：Laura Bertoletti ; Luca Regazzoni ; Aless ; ra Altomare ; Raffaella Colombo ; Mara Colzani ; Giulio Vistoli ; Loredana Marchese ; Marina Carini ; Ersilia De Lorenzi ; Giancarlo Aldini
• 关键词：Beta2-microglobulin ; Reactive carbonyl species ; Dialysis related amyloidosis ; Oxidative stress ; Advanced glycoxidation end products ; Mass spectrometry
• 刊名：Journal of Pharmaceutical and Biomedical Analysis
• 出版年：25 March, 2014
• 年：2014
• 卷：91
• 期：Complete
• 页码：193-201
• 全文大小：1022 K

文摘

By using a high resolution top-down and bottom-up approach we identified and characterized the AGEs of beta₂-microglobulin (尾₂-m) formed by incubating the protein in the presence of glucose and of the main reactive carbonyl species. Glucose induced glycation on the N-terminal residue, while glyoxal (GO) and methylglyoxal (MGO) covalently reacted with Arg3. Carboxymethyl (CM-R) and imidazolinone (R-GO) derivatives were identified in the case of GO and carboxyethyl arginine (CE-R) and methyl-imidazolinone (R-MGO) for MGO. Interestingly, 伪,尾-unsaturated aldehydes [4-hydroxy-2-nonenal (HNE); 4-oxo-2-nonenal (ONE); acrolein (ACR)] did not induce any covalent modifications up to 100 渭M. The different reactivity of 尾₂-m towards the different RCS was then rationalized by molecular modeling studies. The MS method was then applied to fully characterize the AGEs of 尾₂-m isolated from the urine of uremic subjects. CM-R, CE-R and R-MGO were easily identified on Arg3 and their relative abundance in respect to the native protein determined by a semi-quantitative approach. Overall, the AGEs content of urinary 尾₂-m ranged from 0.2 to 1% in uremic subjects. The results here reported offer novel insights and technical achievements for a potential biological role of AGEs-尾₂-m in pathological conditions.