Immunochemical and mass spectrometric analysis of N^ε-(carboxymethyl)lysine content of AGE-BSA systems prepared with and without selected antiglycation agents

The present study was designed to compare surface plasmon resonance (SPR) biosensor, enzyme-linked immunosorbent assay (ELISA), and ultraperformance liquid chromatography−tandem mass spectrometry (UPLC-MS/MS) methods for the analysis of N^ε-(carboxymethyl)lysine (CML) in glucose−bovine serum albumin (BSA) model systems and to investigate the possible inhibitory effect of selected compounds (α-tocopherol, ferulic acid, rutin, thiamin, thiamin monophosphate, and thiamin pyrophosphate) on CML formation. The reported levels of CML detected were dependent upon the method of analysis employed. The highest reported concentrations were obtained with the SPR biosensor, whereas the lowest were found by ELISA. However, a high correlation was observed between these two immunochemical procedures. CML concentrations were dependent upon the type and concentration of the candidate CML inhibitor. All inhibitory compounds investigated, with the exception of α-tocopherol, decreased the level of CML formation in the glucose−BSA system.