in-silico characterization of β-(1, 3)-endoglucanase (ENGL1) from Aspergillus fumigatus by homology modeling and docking studies

During the past few years a significant rise in aspergillosis caused by filamentous fungus Aspergillus fumigatus has been recorded particularly in immunocompromised patients. At present, there are limited numbers of antifungal agents to combat these infections and the situation has become more complex due to emergence of antifungal resistance and side-effects of antifungal drugs. These situations have increased the demand for novel drug targets. Recent studies have revealed that the β-1,3-endoglucanase (ENGL1) plays an essential role in cell wall remodeling that is absolutely required during growth and morphogenesis of filamentous fungi and thus is a promising target for the development of antifungal agents. Unfortunately no structural information of fungal β- glucanases has yet been available in the Protein Databank (PDB). Therefore in the present study, 3D structure of β-(1,3)- endoglucanase (ENGL1) was modeled by using I-TASSER server and validated with PROCHECK and VERIFY 3D. The best model was selected, energy minimized and used to analyze structure function relationship with substrate β-(1,3)-glucan by C-DOCKER (Accelrys DS 2.0). The results indicated that amino acids (GLU 380, GLN 383, ASP 384, TYR 395, SER 712, and ARG 713) present in β-1,3-endoglucanase receptor are of core importance for binding activities and these residues are having strong hydrogen bond interactions with β-(1,3)-glucan. The predicted model and docking studies permits initial inferences about the unexplored 3D structure of the β-(1,3)-endoglucanase and may be promote in relational designing of molecules for structure-function studies.