RESUMO
The present study emphases the comparative proteomic analysis of Escherichia coli Nissle 1917 under cocoti palm wine stress and identified differentially expressed proteins. Protein samples were analyzed by 2-D, MALDI-TOF combined with MS access. In 2-D electrophoresis, eight differentially expressed proteins were identified: five up-regulated, two down-regulated and one newly expressed protein. Protein spots were digested with trypsin for MALDI-TOF-MS analysis; protein sequences were obtained from MASCOT search. Sequences were aligned with template using Swiss Model server. Phyre-2 was used to predict homology modeling, RasMol was used to analyze the modeling structures, PSVS server was utilized to validate the protein structure by Ramachandran's plot analysis, physical and chemical properties were analyzed using ProtParam server, Phylogenetic tree was constructed by Mega4. UniProt search helps to find protein functional information of differentially expressed proteins, involved in catalytic activities, regulation mechanisms, DNA damage stimulus, anti-termination and termination process, protein binding, electron transport mechanism, and cell signaling process functions. A detailed exploration of the proteins under cocoti palm wine stress have provided the composition, structure and functions of the expressed proteins for further investigation.
RESUMO
Flavonoids are the most common group of phenolic compounds that have anti-carcinogenic properties and are the constituents of fruits, vegetables and plant derived beverages. In the present study, Flavonoids were docked to three-dimensional structure of P-glycoprotein which plays an important role in multi drug resistance. A three-dimensional homology model of human P-glycoprotein was built, based on the crystal structure of the 3G5U (Chain A; Structure of a bacterial multidrug ABC transporter) by using Modeller7v7 software. Homology modelling provided a good quality model of the corresponding region in human P-glycoprotein. With the aid of the molecular mechanics and molecular dynamics methods, the final model is obtained and is further assessed by PROCHECK and verify 3D graph programs, which showed that the final refined model is reliable. With this model, a flexible docking study of P-glycoprotein with a group of Flavonoids which were selected from the previous publications was performed. The results indicated THR37, ALA42, ARG40 and ARG47 in P-glycoprotein are important determinant residues in binding as they have strong hydrogen bonding with Flavonoids. These hydrogen binding interactions play an important role for stability of the complex. Among the 10 Flavonoids docked, BiochaninA showed best docking result with P-glycoprotein. Our results may be helpful for further experimental investigations.
