| Comparison of secondary and tertiary trypsin structures from the midgut of Helicoverpa armigera and Plutella xylostella |
| Paper ID : 1278-3IICE (R1) |
| Authors: |
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Somayeh Ebrahimi1, Narges Karam kiani2, Zohreh Farhadi3, Seyed Ali Hemmati *2 1Department of plant protection, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, iran. 2Department of Plant Protection, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran. 3Department of plant protection, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran. |
| Abstract: |
| A “knowledge-based” method of predicting the unknown structure of a protein from a homologous known structure via energetics to recommend a reliable structural is suggested. Prediction methods and structural analysis for realizing some features of trypsin from Helicoverpa armigera Hübner and Plutella xylostella L. including the structure of active site, alkaline pH profile and the secondary structural contents (α-helix and β-strand) are required. For this purpose, similarity searches were carried out using BLASTP through NCBI server and then the reliable structural models of cotton bollworm and Diamond back moth trypsins were built based on Fusarium oxisporum (Schlecht) trypsin crystal structure (PDB: 1GDU) using Modeller 9.21 program. Modeller output contains 10 models and the loop refine module of modeller was used to refine loops and 10 loop-refined models were constructed. The best model was approved by ProCheck, Verify_3D, Errat and Prove programs. QMEAN score, Ramachandran plots and Dfire energy was calculated by Swiss model server to assess the quality and protein conformation free energy score of the predicted models. The best-fitted structural model for H. armigera and P. xylostella was chosen and picked as the 3D structure of midgut trypsin and used for further studies. Another analysis was conducted to further confirm the H. armigera and P. xylostella trypsins model accuracy. Also, the multiple sequence alignment was carried out among the trypsin amino acid sequences using clustal W and espript, version 2.2. Finally, the secondary structural contents of the best-fitted structural model were obtained by DSSP server. The outcomes demonstrated that there is no significant difference between the trypsin structural models of H. armigera and P. xylostella. The aim of the current study was to improve knowledge of prediction tertiary structure models to supply new information about protease structure. The application of theoretical techniques enables us to predict the enzyme structure with high accuracy and this could help in the design of efficient inhibitors for trypsin with perfect properties. |
| Keywords: |
| Helicoverpa armigera, Plutella xylostella, trypsin, Homology modeling, Structural analysis. |
| Status : Paper Accepted (Poster Presentation) |
