摘要
While CrylAc has been known to bind with larval midgut proteins cad- herin, APN （amino peptidase N）, ALP （alkaline phosphatase） and ABCC2 （adenosine triphosphate-binding cassette transporter subfamily C2）, little is known about the recep- tors of Cry2Ab. To provide a clue to the receptors of Cry2Ab, we tested the baseline cytotoxicity of activated Cry 1Ac and Cry2Ab against the midgut and fat body cell lines of Helicoverpa zea and the ovary cell line ofSpodopterafrugiperda （SFg）. As expected, the descending order of cytotoxicity of CrylAc against the three cell lines in terms of 50% lethal concetration （LC50） was midgut （31.0μg/mL） 〉 fat body （59.0μg/mL） and SF9 cell （99.6μg/mL）. By contrast, the fat body cell line （LC50 = 7.55μg/mL） was about twice more susceptible to Cry2Ab than the midgut cell line （16.0/xg/mL）, the susceptibility of which was not significantly greater than that of SF9 cells （27.0μg/mL）. Further, ligand blot showed the binding differences between CrylAc and Cry2Ab in the three cell lines. These results indicated that the receptors of Cry2Ab were enriched in fat body cells and thus largely different from the receptors of CrylAc, which were enriched in midgut cells.
While CrylAc has been known to bind with larval midgut proteins cad- herin, APN （amino peptidase N）, ALP （alkaline phosphatase） and ABCC2 （adenosine triphosphate-binding cassette transporter subfamily C2）, little is known about the recep- tors of Cry2Ab. To provide a clue to the receptors of Cry2Ab, we tested the baseline cytotoxicity of activated Cry 1Ac and Cry2Ab against the midgut and fat body cell lines of Helicoverpa zea and the ovary cell line ofSpodopterafrugiperda （SFg）. As expected, the descending order of cytotoxicity of CrylAc against the three cell lines in terms of 50% lethal concetration （LC50） was midgut （31.0μg/mL） 〉 fat body （59.0μg/mL） and SF9 cell （99.6μg/mL）. By contrast, the fat body cell line （LC50 = 7.55μg/mL） was about twice more susceptible to Cry2Ab than the midgut cell line （16.0/xg/mL）, the susceptibility of which was not significantly greater than that of SF9 cells （27.0μg/mL）. Further, ligand blot showed the binding differences between CrylAc and Cry2Ab in the three cell lines. These results indicated that the receptors of Cry2Ab were enriched in fat body cells and thus largely different from the receptors of CrylAc, which were enriched in midgut cells.
