Safety assessment of insecticidal proteins: A case study utilizing His-tagged protein to determine the safety of Mpp75Aa1.1, a new ETX_MTX2 protein that controls western corn rootworm

Wang, C.; Bean, G. J.; Chen, C. J.; Kessenich, C. R.; Peng, J.; Visconti, N. R.; Milligan, J. S.; Moore, R. G.; Tan, J.; Edrington, T. c.; Li, B.; Giddings, K. S.; Bowen, D.; Luo, J.; Ciche, T.; Moar, W. J.

doi:10.1101/2022.03.28.486136

bioRxiv · 10.1101/2022.03.28.486136

Safety assessment of insecticidal proteins: A case study utilizing His-tagged protein to determine the safety of Mpp75Aa1.1, a new ETX_MTX2 protein that controls western corn rootworm

Wang, C.·Bean, G. J.·Chen, C. J.·Kessenich, C. R.·Peng, J.·Visconti, N. R.·Milligan, J. S.·Moore, R. G.·Tan, J.·Edrington, T. c.·Li, B.·Giddings, K. S.·Bowen, D.·Luo, J.·Ciche, T.·Moar, W. J.

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Abstract

The recently discovered insecticidal protein Mpp75Aa1.1 from Brevibacillus laterosporus is one member of the ETX_MTX family of beta-pore forming proteins ({beta}-PFPs) expressed in genetically modified (GM) maize to control western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte). In this paper, bioinformatic analysis establishes that although Mpp75Aa1.1 shares varying degrees of similarity to members of the ETX_MTX2 protein family, it is unlikely to contribute to any allergenic, toxic, or otherwise adverse biological effects. The safety of Mpp75Aa1.1 is further supported by a weight of evidence including evaluation of history of safe use (HOSU) of ETX_MTX2 proteins. Assessments using either purified Mpp75Aa1.1 protein or a poly-histidine-tagged (His-tagged) variant of the Mpp75Aa1.1 protein demonstrate that both forms of the protein are heat labile at temperatures at or above 55 {degrees}C, degraded by gastrointestinal proteases within 0.5 min, and have no adverse effects in acute mouse oral toxicity studies at a dose level of 1920 or 2120 mg/kg body weight. Results also indicate that the domain-based protein characterization should be considered as part of the weight of evidence for the safe consumption of food or feed. Furthermore, these results support the use of His-tagged proteins as suitable surrogates for assessing the safety of their non-tagged parent proteins.

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Wang, C., Bean, G. J., Chen, C. J., Kessenich, C. R., Peng, J., Visconti, N. R., Milligan, J. S., Moore, R. G., Tan, J., Edrington, T. c., Li, B., Giddings, K. S., Bowen, D., Luo, J., Ciche, T., Moar, W. J.. 2022-03-28. Safety assessment of insecticidal proteins: A case study utilizing His-tagged protein to determine the safety of Mpp75Aa1.1, a new ETX_MTX2 protein that controls western corn rootworm. https://doi.org/10.1101/2022.03.28.486136

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