5ycz

Publication Abstract from PubMed

BACKGROUND: Pesticidal property of many Kunitz type inhibitors is reported previously. But, the mechanism of action is not well established. In the present study, activity of alocasin against Aedes aegypti is demonstrated and the structure-activity relationship of this Kunitz type inhibitor is explained through X-ray structure analyses. RESULTS: Alocasin was purified from mature rhizomes of Alocasia as a single polypeptide chain of approximately 20 kDa. The structure at 2.5A resolution revealed Kunitz-type fold but variation in the loop regions makes this structure unique. One of the loops with one disulfide bridge is replaced by a long loop with two bridges. An alignment of homologous sequences revealed that this long loop contains a conserved Arg residue and found to interact with the catalytic Ser residue of Trypsin-like enzymes by modelling studies. Anti-Aedes aegypti activity of alocasin has been examined and discussed in detail. The in-vitro activity of alocasin against midgut proteases of Aedes aegypti showed profound inhibition. Further, the morphological changes on larvae upon treatment of alocasin revealed its activity against Ae. ageypti. Docking studies of alocasin with Trypsin (5G1), a midgut protease which involve in the development cycle and blood meal digestion illustrated its insecticidal activity. CONCLUSION: Three-dimensional structure of alocasin was determined and its structure-function relationship was established for its anti Ae. aegypti activity.

Crystal structure of a novel Kunitz type inhibitor, Alocasin with Anti-Aedes aegypti activity targeting midgut proteases.,Vajravijayan S, Pletnev S, Pletnev VZ, Nandhagopal N, Gunasekaran K Pest Manag Sci. 2018 May 7. doi: 10.1002/ps.5063. PMID:29737039^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.