Abstract：Objective To study the digestive stability of recombinant Cry1Ab/Cry2Aj, G10evo (EPSPS) proteins of the genetically modified maize in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Methods An in vitro model of gastrointestinal digestion system was established according to the national standard. Samples were digested at 5 mg/mL concentration in the simulated gastric juice and 2 mg/mL concentration in the simulated intestinal fluid. 200μL simulated fluid was taken out at intervals of 0s, 15s, 2min, 30min and 60min respectively, and were added with buffer. The reaction was stopped by boiling water bath for 5min. The proteins that had been digested in SGF/SIF were subjected to SDS-PAGE, and the results were observed through the Gel Imaging System. Results The stable control protein soybean trypsin inhibitor (STI) was not totally digested by SGF/SIF after 60min. The labile control protein α-casein was rapidly digested by the SGF/SIF within 0-15s. Recombinant Cry1Ab/Cry2Aj protein was digested within 0-15s in SGF/SIF. Recombinant G10evo(EPSPS) protein was digested within 0-15s in SGF, and within 2-30min in SIF. Conclusions Recombinant Cry1Ab/Cry2Aj, G10evo (EPSPS) proteins of the genetically modified maize are considered to be digested unstably in SGF/SIF and easy to be degraded.
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