<p style="text-align: justify;"><b>Dietary Exposure</b></p>

<p style="text-align: justify;">Maize line MS3 was intended mainly for use in animal feed. The major human food uses for maize are extensively processed starch and oil fractions prepared by wet or dry milling procedures and include products such as corn syrup and corn oil, bran, grits, meal and flour. The human food uses of MS3 maize grain were not expected to be different from the uses of non-transgenic field maize varieties. As such, the dietary exposure of people to grain from MS3-derived maize hybrids was not prediced to differ from that for other commercially available field corn varieties. Furthermore, since neither of the introduced proteins were detected in the corn grain, there would be no dietary exposure to these introduced proteins.</p>

<p style="text-align: justify;"><b>Nutritional Data</b></p>

<p style="text-align: justify;">The composition of grain from MS3-derived hybrid maize was compared to grain from non-transgenic maize. Parameters such as moisture, fibre, fat protein, ash, starch, oil, fatty acids and the amino acid composition were compared with no significant differences being observed. The use of grain from MS3-derived maize hybrids would therefore have no significant impact on the nutritional quality of the food supply.</p>

<p style="text-align: justify;"><b>Toxicity</b></p>

<p style="text-align: justify;">The low potential for toxicity of transgenic maize line MS3 was demonstrated by examining the amino aid sequence homology and the characteristics of the proteins. An amino acid sequence comparison of the barnase enzyme with the sequences of known protein allergens and toxins in three public domain databases did not reveal any significant homologies, other than with ribonucleases from other bacilliform bacteria. Similar comparative analyses were completed for PAT enzyme. The amino acid sequence of PAT enzyme did not show significant homologies with any toxins or allergens, except with other phosphinothricin acetyltransferases originating from different organisms.<br />
The full nucleotide sequence of the barnase gene was provided. The RNAse enzyme, encoded by the barnase gene, was a small single-domain protein, containing no disulfide bonds, metal-ion cofactors or other non-peptide components. When heated, it unfolded completely into an inactive form.</p>

<p style="text-align: justify;">No toxic or allergic effects were expected from PAT as acetyltransferases are ubiquitous in nature, do not possess proteolytic or heat stability and are highly substrate specific. PAT has a extremely high substrate specificity for L-PPT and dimethylphosphinothricin (DMPT), and experimental data clearly showed that neither L-PPT&#39;s analog L-glutamic acid, D-PPT, nor any other amino acid can be acetylated by the PAT enzyme.</p>

<p style="text-align: justify;"><b>Allergenicity</b></p>

<p style="text-align: justify;">The barnase RNAse and PAT enzymes are not likely to be allergenic. In addition to the amino acid sequence homology searches describe above, the potential for allergenicity of the PAT enzyme was assessed based upon the characteristics of known food allergens (stability to digestion, stability to processing). Unlike known protein allergens, these studies demonstrated that the PAT enzyme was rapidly inactivated when subjected to typical mammalian stomach conditions. In summary, the barnase RNAse and PAT enzyme were not derived from allergenic sources, do not share amino acid sequence homology with known allergens, and do not possess the physiochemical properties (heat and proteolytic digestion stability) normally associated with allergens.</p>
