Advanced glycation end products: a highly complex set of biologically relevant compounds detected by mass spectrometry

Structural information on 'AGE-peptides,' a class of substances belonging t o advanced glycation end products (AGE) and originating by proteolysis of g lycated proteins, was gained through various analytical approaches on the m ixture produced by proteinase K digestion of in vitro glycated bovine serum albumin. Both matrix-assisted laser desorption/ionization mass spectrometr y (MALDI-MS) and high-performance liquid chromatography/electrospray ioniza tion mass spectrometry (HPLC/ESI-MS) were employed, and the results were co mpared with those from conventional spectroscopic methods (UV, fluorescence , gel permeation). The data acquired by the various techniques all depict t he digestion mixtures as highly complex, with components exhibiting molecul ar mass in the range 300-3500 Da. In the analysis of HPLC/ESI-MS data, iden tification of AGE-peptides was facilitated by 3D mapping. Structural inform ation was gained by means of multiple mass spectrometric experiments. Copyr ight (C) 2001 John Wiley & Sons, Ltd.