PROTEOMIC ANALYSIS OF WHEAT STORAGE PROTEINS: A PROMISING AFSOAS^TO UNDERSTAND THE GENETIC AND MOLECULAR BASES OF GLUTEN COMPONENTS

摘要

The proteome is composed of Ihe whole set of proteins present in a given tissue, cell, or in sub-cellular components of a living organism at a given time1. The identification of all the proteins expressed, the study of their genetic determinism (gene location and sequence), the study of their possible polymorphism through post-translational and post-traductional modifications, and the identification of their function in physiological metabolism are the major tasks that comprise the proteomic approach2. Wheat storage proteins (WSP) have been extensively analysed in the two last decades (for a review, see Kasarda , Lafiandra , Shewry5). These early findings on genetic determinism, allelic diversity, protein sequences, and functional properties were in fact the main steps of proteomic analysis long before this approach became a powerful technique, thanks to progress in mass spectrometry. Several studies have been carried out on the endosperm proteins using proteomic tools. For example, total endosperm proteins extracted from mature wheat kernels have been analysed both in normal and heat-stressed growing conditions6"11. Two dimensional electrophoresis (2-DE), which is currently the most powerful method for protein separation12, has not often been used to analyse either gliadins or glutenins. This technique was recently used to characterise wheat endosperm proteins by determining their N-terminal amino acid sequences10'13. Proteomic analysis offers new opportunities to investigate important questions concerning the gluten proteins (gliadins and glutenins) which are not usually separated together on the same gel. Some examples of proteomic approaches are described below.