THE EXPRESSED PROTEIN IN GLYPHOSATE-TOLERANT SOYBEAN, 5-ENOLYPYRUVYLSHIKIMATE-3-PHOSPHATE SYNTHASE FROM AGROBACTERIUM SP STRAIN CP4, IS RAPIDLY DIGESTED IN-VITRO AND IS NOT TOXIC TO ACUTELY GAVAGED MICE

The safety of 5-enolpyruvylshikimate-3-phosphate synthase enzyme deriv ed from Agrobacterium sp. strain CP4 (CP4 EPSPS) was assessed. CP4 EPS PS is the only protein introduced by genetic manipulation that is expr essed in glyphosate-tolerant soybeans, which are being developed to pr ovide new weed-control options for farmers. Expression of this protein in plants imparts high levels of glyphosate tolerance. The safety of CP4 EPSPS was ascertained by evaluating both physical and functional c haracteristics. CP4 EPSPS degrades readily in simulated gastric and in testinal fluids, suggesting that this protein will be degraded in the mammalian digestive tract upon ingestion as a component of food or fee d. There were no deleterious effects due to the acute administration o f CP4 EPSPS to mice by gavage at a high dosage of 572 mg/kg body wt, w hich exceeds 1000-fold the anticipated consumption level of food produ cts potentially containing CP4 EPSPS protein. CP4 EPSPS does not pose any important allergen concerns because this protein does not possess characteristics typical of allergenic proteins. These data, in combina tion with seed compositional analysis and animal feeding studies, supp ort the conclusion that glyphosate-tolerant soybeans are as safe and n utritious as traditional soybeans currently being marketed.