“Theoretical studies of structural and functional characteristics of

XVI Simpósio Brasileiro de Química Teórica – SBQT 2011
Ouro Preto – MG, 20-23 Novembro de 2011
30 Anos SBQT
“Theoretical studies of structural and functional characteristics of
Fusarium solani β-glucosidase by molecular modeling”
Nascimento Soelange B (PG), Alencar Nelson AN (PG), Sousa Robson PM(G),
Pinheiro Silvana S(PG), Silva Natalia F(PG), Silva Alessandra P(G), Costa Kelly
M(PG), Oliveira Renata LS (PG), Lameiro Jerônimo S (PQ), Alves Cláudio N (PQ)
Universidade Federal do Pará, CP 11101, 66075-110, Belém, PA, Brasil.
Key-words: Fusarium solani, β-glucosidase, Molecular docking
β-glucosidase is a glycoside hydrolase 3 (GH3) and in fungi this enzyme is related
with the synthesis of cell wall. Fusarium solani is pathogenic fungi responsible for
disease on ~100 genera of plants and it is also associated with opportunistic
fungal infections and keratitis in humans. Thus, selective inhibitors for βglucosidase appears as new strategies for suppress fungal diseases. In this study,
we have used molecular modeling to predict the three dimensional structure. In
addition, to explain the interaction between PUGNAc and six analogues
inhibitors and β-glucosidase enzyme was analyzed in order to understand
inhibition mechanism of β-glucosidase. The structure three-dimensional of βglucosidase from F. solani (FsbGlc) was predicted by molecular homology using
as template code PDB 2OXN from Vibrio cholera (VcNagZ). The interaction study
for FsbGlc-PUGNAc and VcNagZ-PUGNAc complexes were analyzed by molecular
docking. The model was built by Modeller9v8 program and docking simulation
was performed using Vina v1.5.4 program with AutoDock Tools 4.2. Our model
had 25.5% sequence identity and was validated by Ramachandran plot with
86.6% of amino acid residues within regions of very favorable and RMSD of 0.5 Å.
The modeled protein FsbGlc active site remained conserved and docking study
showed low affinity energy and good correlation with logKI values
for all
PUGNAc analogues in both FsbGlc-PUGNAc and VcNagZ-PUGNAc complexes
measured by the kinetic Ki data with R = 0.898 and R = 0.897 respectively.
These results are promising and further studies are needed to validate the
dynamic flexibility of the protein modeled.
Support: UFPA, LPDF, CNPq, CAPES.