THE SEED STORAGE PROTEINS FROM LUPINUS-ALBUS

Studies on lupin seed storage proteins have been performed using purification techniques that are often time-consuming and lead to poor resolution between the individual globulins. In this paper we have utilized anion exchange chromatography on the MONO Q column of the FPLC as a high-resolution, easy and rapid method to fractionate the three main globulins from two cultivars of Lupinus albus, namely the sweet cv Multolupa and the bitter cv Torres Vedras. The structure of the purified globulins, designated by gamma-, beta- and alpha-conglutins, was studied by electrophoresis performed under non-denaturing conditions, under denaturing, non-reducing conditions and denaturing, reducing conditions, and by two-dimensional electrophoresis. We have also developed a rapid, easy and sensitive method to determine the polypeptide chain composition of proteins or protein subunits which is based on the lateral diffusion of 2-mercaptoethanol during electrophoresis. We propose a nomenclature for the polypeptide chains and individual subunits of L. albus globulins that can be extended to other seed storage proteins.