Electrophoretic techniques for the separation of peritrophic membrane proteins from Helicoverpa armigera

Author of the article:LI YiPing1** WU JunXiang1 LIANG GeMei2 GUO YuYuan2 YUAN XiangQun1

Author's Workplace：1. Key Laboratory of Applied Entomology, College of Plant Protection, Northwest A & F University, Yangling712100, China; 2. State Key Laboratory of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing100193, China

Key Words：Helicoverpa armigera, peritrophic membrane protein, separation, electrophoretic techniques

Abstract： The effects of the separation of peritrophic membrane (PM) proteins from Helicoverpa armigera (Hübner)were compared using different treatment methods, different numbers of PM proteins and different electrophoretic conditions, in order to select the optimal technique. The results of SDSPAGE show that, although freezedrying is recommended for the separation of PM proteins, nearly equivalent results were achieved with and without freeze drying. Although one, three and five strips of PM protein could be completely separated by SDSPAGE, five strips provide a more reliable representation of the population. There was no significant difference in the results obtained by SDSPAGE using separation gel concentrations of 8%、10% and 12% and a stacking gel concentration of 5%. The optimum separation gel concentration was 12%. Treating PM with anhydrous trifluoromethanesulfonic acid before separation with NuPAGE resulted in approximately 30 types of PM protein, far exceeding the 16-20 types of proteins previously obtained from H. armigera. Furthermore, only a small amount of PM material was needed using this method. However, although this method was the most effective it is considerably more expensive than the alternatives.