Improvement The Quality of 'Soya Bean Seed Storage Proteins by Genetic Engineering Cdna Encoding G2 Subunit

Abstract

The goal of this work is to improve nutritional quality of soybean seed proteins by altering cDNA-encoding G2 subunit of Soybean glycinin to be capable of self-assembly in vitro. Two plasmids were constructed; one designated pSP65/G4SacG2 and the other pSP65/G45<7cG2HG4. The observation that basic chain did not tolerate modification and that a 21 amino acids deletion in the basic chain of G4 proglycinin inhibited self-assembly into trimers [I], make the introduction of Sac fragment of GY4 to GY2 is a possible key factor in getting G2 self-assemble. pSP65/G45acG2HG4 construct includes, in addition to G4 Sac fragment, the acidic chain of GY4 which was proved to tolerate an introduction of three Met residues. This construct, therefore, had the ability to self-assemble in vitro and in the mean time the ability to harbor a number of Met residues. The ability of these constructs to assemble into oligomer similar to those that occur in the seed was tested.