Safety assessment of Cry1Ab/Ac fusion protein

Food Chem Toxicol. 2009 Jul;47(7):1459-65. doi: 10.1016/j.fct.2009.03.029. Epub 2009 Mar 31.


Cry1ab/ac gene was fused by both the cry1ab gene (GenBank Accession No. X54939) and the cry1ac gene (GenBank Accession No. Y09787), which was widely used in genetically modified (GM) rice, cotton, maize and so on. In order to support the safety assessment of GM food or feed products containing Cry1Ab/Ac protein, sufficient quantities of Cry1Ab/Ac protein were produced in Escherichia coli for in vitro evaluation and animal studies. The Cry1Ab/Ac protein does not possess the characteristics associated with food toxins or allergens, i.e., it has no sequence homology with any known allergens or toxins, and no N-glycosylation sites, can be rapidly degraded in gastric and intestinal fluids, and is devoid of adverse effects in mice by gavage at a high dose level of 5g (Cry1Ab/Ac protein)/kg body weight. In conclusion, there is a reasonable certainty of no harm resulting from the inclusion of the Cry1Ab/Ac protein in human food or animal feed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / analysis
  • Amino Acid Sequence
  • Animals
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / pharmacokinetics
  • Bacterial Proteins / toxicity*
  • Blood Chemical Analysis
  • Drug Stability
  • Endotoxins / pharmacokinetics
  • Endotoxins / toxicity*
  • Escherichia coli / metabolism
  • Female
  • Glycosylation
  • Hemolysin Proteins / pharmacokinetics
  • Hemolysin Proteins / toxicity*
  • Hot Temperature
  • Hydrolysis
  • Insecticides / pharmacokinetics
  • Insecticides / toxicity*
  • Male
  • Mice
  • Molecular Sequence Data
  • Organ Size / drug effects
  • Oryza / metabolism
  • Plants, Genetically Modified / metabolism
  • Recombinant Fusion Proteins / pharmacokinetics
  • Recombinant Fusion Proteins / toxicity


  • Allergens
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Endotoxins
  • Hemolysin Proteins
  • Insecticides
  • Recombinant Fusion Proteins
  • insecticidal crystal protein, Bacillus Thuringiensis