Non-glycosylated transferrin expressed in monocots

Abstract

Disclosed are compositions and methods of making non-glycosylated transferrin protein in transgenic monocot plants.

What is claimed is: 
     
         1 . A pharmaceutical composition comprising:
 a fusion protein comprising non-glycosylated transferrin and a therapeutic protein, wherein the fusion protein is expressed in and purified from a monocot seed.   
     
     
         2 . A cell culture media composition comprising:
 a fusion protein comprising non-glycosylated transferrin and a therapeutic protein wherein the fusion protein is expressed in and purified from a monocot seed.   
     
     
         3 . A transgenic monocot seed-derived composition comprising:
 a fusion protein comprising non-glycosylated transferrin and a therapeutic protein wherein the fusion protein is expressed in and purified from a monocot seed.   
     
     
         4 . A food composition comprising:
 a fusion protein comprising non-glycosylated transferrin and a therapeutic protein wherein the fusion protein is expressed in and purified from a monocot seed.   
     
     
         5 . The composition of any of  claims 1 - 4 , formulated for injectable delivery. 
     
     
         6 . The composition of any of  claims 1 - 4 , formulated for oral delivery. 
     
     
         7 . The composition of any of  claims 1 - 4 , wherein the therapeutic protein is insulin or proinsulin. 
     
     
         8 . A transgenic monocot seed-derived composition, selected from the group consisting of a whole-seed food composition, a flour composition, an extract composition and a malt composition, comprising a fusion protein comprising non-glycosylated transferrin and a therapeutic protein. 
     
     
         9 . The seed-derived composition of  claim 8 , wherein the fusion protein comprising non-glycosylated transferrin and a therapeutic protein constitutes at least 0.1% of the dry weight of the seed-derived composition. 
     
     
         10 . The composition of  claim 8  or  claim 9 , wherein the therapeutic protein is insulin or proinsulin. 
     
     
         11 . A serum-free cell culture medium comprising an extract of transgenic monocot seed comprising a seed-expressed fusion protein comprising:
 a seed-specific signal sequence capable of targeting a polypeptide linked thereto to a protein storage body;   non-glycosylated transferrin; and   a therapeutic protein.   
     
     
         12 . The serum-free cell culture medium of  claim 11 , wherein the therapeutic protein is insulin or proinsulin. 
     
     
         13 . A method of producing a recombinant fusion protein comprising transferrin and a therapeutic protein in monocot plant seeds, comprising the steps of:
 (a) transforming a monocot plant cell with a chimeric gene comprising
 (i) a seed maturation-specific promoter; 
 (ii) a first DNA sequence, operably linked to said promoter, said first DNA sequence encoding a signal sequence targeting a polypeptide linked thereto to a protein storage body of a monocot plant seed cell; and 
 (iii) a second DNA sequence, linked in translation frame with the first DNA sequence, encoding a fusion protein comprising transferrin and a therapeutic protein, 
 wherein the first DNA sequence and the second DNA sequence together encode a fusion protein comprising the signal sequence, a therapeutic protein and transferrin; 
   (b) growing the monocot plant from the transformed monocot plant cell for a time sufficient to produce seeds containing the fusion protein; and   (c) harvesting the seeds from the plant.   
     
     
         14 . The method of  claim 13 , wherein the first DNA sequence encoding a signal sequence targeting a polypeptide linked thereto to a protein storage body of a monocot plant seed cell encodes a glutelin signal sequence. 
     
     
         15 . The method of  claim 13 , wherein the fusion protein constitutes at least 0.01% seed weight of the harvested seeds. 
     
     
         16 . A transformed rice plant produced according to the method of  claim 13 . 
     
     
         17 . A transformed rice seed produced according to the method of  claim 13 .