Mass spectrometry in the characterization of cereal seed proteins.

In less then a decade, applications of matrix-assisted laser desorption/ionisation (MALDI) and electrospray ionisation (ESI) mass spectrometry to the investigation of prolamins have rapidly evolved from measurements of the molecular mass of isolated proteins to a proteomic approach attempting to characterise the complete protein pattern in the seed. Mass spectrometry is currently making significant contributions to the understanding of the composition and structure of the gluten proteins and, in turn, to the elucidation of structure-function relationships. Results obtained using mass spectrometry, including determination of the molecular masses of prolamins, direct verification of gene-derived sequences, determination of the number of cysteine residues and localisation of disulphide bonds, investigation of the gluten toxicity for celiac patients, qualitative and quantitative determination of gliadins in food and determination of the protein pattern and its modification during seed maturation by proteomic approaches, are summarised here, to illustrate current trends and individuate possible future perspectives.