The role of mass spectrometry in the study of non-enzymatic protein glycation in diabetes

Mass spectrometry has been applied successfully to the study of non-enzymat ic protein glycation, which is a topic of wide interest in the diabetes fie ld Low- and high-resolution mass spectra, GC/MS, and collisional activation spectroscopy allow the structural identification and quantitative evaluati on of advanced glycation end-products, which represent important molecules for monitoring diabetes. More recently available techniques, such as ESI an d MALDI/MS, have had a significant impact on analytical problems in diabete s. In particular MALDI has been applied to the study of protein glycation i n in vitro and in vivo conditions, because the number of glucose molecules that condense onto the protein can be easily determined by this approach. I n the former case, glycation kinetics have been studied in various sugars a nd sugar concentrations, proteins, and buffer concentrations; in the latter comparisons of MALDI spectra of circulating proteins from healthy and diab etic subjects determine the exposure of patients to high glucose levels. Th e method has been applied to an evaluation of the glycation level of immuno globulins, and indicates that glycation takes place preferentially on the F ab fragment of the protein, data are relevant in relating immunological imp airment with glycation-induced changes in the functionality of immunoglobul ins. (C) 2000 John Wiley & Sons, Inc.