Many protein allergens are glycosylated, raising the possibility that the glycosyl groups may contribute to their allergenicity (Jenkins et al., 1996). This is potentially relevant when considering the allergenicity of novel proteins for which glycosylation patterns may differ substantially from their native counterparts. The search for potential N-glycosylation sites found four such sites on the Cry1Ab/Ac protein but in vitro assays proved that there was no N-glycosylation site on the Cry1Ab/Ac protein actually.