Effect of Cu(ii) on in vitro glycation of human serum albumin by methylglyoxal: a LC-MS-based proteomic approach. Issue 2 (21st December 2016)

• Record Type: Journal Article
• Authors: Ramirez Segovia, Alejandra Sarahi; Wrobel, Kazimierz; Acevedo Aguilar, Francisco Javier; Corrales Escobosa, Alma Rosa; Wrobel, Katarzyna
• Is Part Of: Metallomics. Volume 9:Issue 2(2017)
• Page Start: 132
• Page End: 140
• Publication Date: 2016-12-21
• Subjects: Metals -- Physiological effect -- Periodicals; 572.51
• DOI: 10.1039/c6mt00235h
• Languages: English
• ISSNs: 1756-5901

Abstract

Abstract : LC-MS peptide mapping with ProteinScape and MaxQuant demonstrated concentration-dependent Cu(ii ) effect on MGo-derived HSA modification. Abstract : It has been reported that glycation of human serum albumin (HSA) changes its capability for copper binding whereas the increase of free copper might have an impact on protein glycation – a key process in diabetes progression. In this work, proteomic analysis of non-glycated HSA and HSA glycated with methylglyoxal (MGo) in the absence or in the presence of Cu(ii ) (0.1; 1.0; 5.0 mg Cu L −1 ) has been undertaken. Trypsin hydrolysates were subjected to capillary HPLC-ESI-QTOF-MS and MS/MS. Raw data were analyzed using two proteomic platforms: MaxQuant (; Web:http://maxquant.org/ ) and ProteinScape (Bruker). Considering seven MGo-derived modifications, the sequence coverage was 98% for non-modified HSA and ≥93% for HSA incubated with MGo or MGo + Cu(ii ). Peptide mapping yielded 76 identical peptides in all samples though important differences were found between non-modified HSA and protein glycated with or without Cu(ii ). Overall, 46 peptides with residues from 1 to 3 modified were detected/sequenced; the MGo-derived modifications found were: hydroimidazolone, argpyrimidine, N ε -carboxyethyl-lysine and S -carboxyethyl-cysteine; 39 modified sites were identified (22 on arginine, 12 on lysine, and 5 on cysteine) and among them, 27 were common for ProteinScape and MaxQuant. The count of the modified peptides and the comparative analysis of their abundance in different samples indicated that Cu(ii ) at physiological and sub-physiological concentrations inhibited HSA glycation as compared to the glycation of the Cu-devoid protein; at higher concentrations (5 mg Cu L −1 ), this inhibitory effect tends to be inverted. The results obtained suggest that increased protein glycation might be associated with Cu-deficiency and with excessive Cu(ii ) concentrations, calling for more detailed studies performed on real-world samples with a strict control of copper concentration.