Analysis of Digestive Stability in Simulative Digestive Tract Fluid and Heat Stability of Cry1Ie Protein

doi:10.13560/j.cnki.biotech.bull.1985.2015.11.028

Abstract

Abstract: Due to the high virulence to Asian corn borer(Ostrinia furnacalis)of Cry1Ie, this protein had applied into the germplasm creating of transgenic insect-resistant maize. To evaluate the food safety of Cry1Ie protein, this study carried out the digestion and heat stability assays. Using the expressing vector which the laboratory has constructed, the Cry1Ie protein(81 kD)was expressed in Escherichia coli, and the high purity protein was obtained using Ni-NTA chromatography and Superdex-75 size-exclusion chromatography. The results of artificial digestion assay showed that Cry1Ie was degraded rapidly within 15 s in simulated gastric fluid and intestinal fluid, without any peptide left in SDS-PAGE. In the heat stability assay, Cry1Ie was not stable in the extracting solution of maize meal, and most was degraded within 30 min under 100℃. In the bioassay of the Asian corn borer(Ostrinia furnacalis), it suggested that Cry1Ie lost the bio-activity after the treatment of digestion and heat. In conclusion, Cry1Ie was not stable in the gastrointestinal fliud and the heat treatment, which had lost the bio-activity to the Asian corn borer(Ostrinia furnacalis).

Key words: transgenic, Cry protein, digestive stability, heat stability, insect-resistance

Li Xinzhu, Geng Lili, Gao Jiguo, Zhang Jie. Analysis of Digestive Stability in Simulative Digestive Tract Fluid and Heat Stability of Cry1Ie Protein[J]. Biotechnology Bulletin, 2015, 31(11): 214-221.

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