Compositions and methods for altering amino acid content of proteins

Abstract

Methods and compositions for altering amino acid composition of a protein of interest are provided, particularly proteins whose three-dimensional structure is unknown. The method comprises creating interacting molecules to the native protein and selecting for engineered proteins which retain the native conformation by antibody binding. In this manner, the levels of essential amino acids in a protein can be increased yet the biological activity of the protein maintained.

1 . An engineered vegetative storage protein comprising an amino acid sequence which differs from the amino acid sequence of the native vegetative storage protein, wherein said engineered protein has an altered amino acid composition in comparison to said native protein, wherein said altered amino acid composition comprises an increase in the content of an essential amino acid compared to said native protein.  
     
     
         2 . The engineered vegetative storage protein of  claim 1 , wherein said increase in an essential amino acid is to at least 10% of the engineered vegetative storage protein.  
     
     
         3 . The engineered vegetative storage protein of  claim 1 , wherein said increase in the content of an essential amino acid is an increase in methionine content to at least 10% of the engineered vegetative storage protein.  
     
     
         4 . A transformed cell expressing the engineered vegetative storage protein of  claim 1 .  
     
     
         5 . A transformed plant comprising the cell of  claim 4 .  
     
     
         6 . The plant of  claim 5 , wherein said plant is a dicot.  
     
     
         7 . The plant of  claim 6 , wherein said dicot is soybean.  
     
     
         8 . A transformed seed of the plant of  claim 5.