Serine proteases represent the predominant protease in the gut of Culex pipiens mosquito larvae
Amrutha M, Shiji TM, Kannan Vadakkadath Meethal
Many insects including mosquitoes digest proteins in the diet with the help of different kinds of proteases secreted in the gut. Different classes of protease inhibit the activity of different kinds of proteases. Thus the kind of proteases present in the gut can be identified using synthetic proteases of known specificity. In this study the contribution of different types of protease in the gut of Culex pipiens mosquito larvae towards protein digestion is identified using synthetic protease inhibitors. Benzamidine Hydrochloride (BHC), Phenyl Methane Sulphonyl Fluride (PMSF), both serine protease inhibitors, inhibited the gut protease activity of Culex pipiens mosquito larvae to the extent of 37.03±1.24% and 78.16±4.17% respectively. A synthetic cysteine protease inhibitor, N-Ethyle Maleimide (NEM), inhibited the gut protease activity of larvae of Culex pipiens up to 15.85±1.66 %. This indicates that the major protease in the gut of Culex pipiens belong to the class of serine proteases. Thus targeting serine proteases with synthetic or naturally occurring plant protease inhibitors will be an ideal strategy for the control of mosquitoes.