Recombinant Peptide

Objective
Hepatitis C infection is one of the most common chronic infectious diseases in the world and about 3-5 million people are infected with this infection annually. Unfortunately, despite recent advances, there are still widespread problems for the treatment of these people and many needs have not been met. As a result, there is an urgent need for more effective treatment strategies to treat this disease. One of these new therapeutic approaches is the use of recombinant proteins, which have no side effects for the patient and at the same time are cheap and available.
Materials and methods
To conduct this study, the three-dimensional structures of virus proteases (NS2, NS3, NS4A, NS5A and NS5B) and recombinant peptide CLF36, were obtained. The chemical structure of new generation drugs was also downloaded from PubChem. To evaluate the stability of the predicted structures and to ensure the accuracy of the third structure of proteins, molecular dynamics simulations were performed using GROMACS software version 2019 and in a duration of 10 nanoseconds. Then, to evaluate the antiviral properties of the peptide, molecular docking was performed for peptides and drugs under static conditions. To evaluate the stability of the complexes, based on the results obtained from molecular docking, complexes with negative values of free binding energy were selected to perform molecular dynamics simulations. Finally, the obtained results were evaluated under dynamic conditions in GROMACS software. The engineered peptides were then designed according to the results and the sequence of the best engineered peptides was sent for synthesis. After cloning and expression of the recombinant peptide in the yeast host, the IC50 level of the peptide on the Huh7.5 liver cell line was determined and the virus-infected cells were treated with the desired peptide. After extracting RNA from the cells, the virus loaded in the sample. Were measured.
Results
Among the results obtained from various dockings performed between virus proteases and recombinant peptides and commercial drugs, it was found that the peptide-binding strength (average -99.92) was much higher than other drugs (average -61.54). This indicates the high antiviral property of the recombinant peptide. The results of molecular dynamics showed that the values of rmsd and hydrogen bonds and binding energy for CLF36 peptide bound to virus proteases compared to other drugs indicate a stronger binding of this peptide. In addition, the engineered peptide showed stronger antiviral activity compared to the natural peptide (binding energy was 8 units stronger). Examination of the function of the peptide in vitro also showed that this peptide has a stronger antiviral effect compared to drugs in that it was able to completely prevent the virus from multiplying in cells.
Conclusions
The final results of this study indicated that recombinant peptide, has strong antiviral properties. However, to confirm these results, additional laboratory studies are needed.