Characterization and In Silico Analysis of The Structural Features of GCSF Derived from Lysates of Escherichia coli

Objective Granulocyte colonystimulating factor (GCSF) has a wide variety of functions including stimulation of hematopoiesis and proliferation of granulocyte progenitor cells. Recombinant human GCSF (rhGCSF) is used for treatment of neutropenia in patients receiving chemotherapy. The mature bloodstream neutrophils express GCSF receptor (GCSFR), presenting a significant and specific mechanism for circulating GCSF clearance. Computational studies are essential bioinformatics methods used for characterization of proteins with regard to their physicochemical properties and 3D configuration, as well as protein–ligand interactions for recombinant drugs. We formerly produced rhGCSF in E. coli and showed that the isolated protein had unacceptable biological activity in mice. In the present paper, we aimed to characterize the purified rhGCSF by analytical tests and developed an in vivo model by computational modelling of GCSF. Materials and Methods In this experimental study, we analyzed the purified GCSF using the analytical experiments. Then, the crystalline structure was extracted from Protein Data Bank (PDB) and molecular dynamics (MD) simulation was performed using Gromacs 5.1 package under an Amber force field. The importance of amino acid contents of GCSF, to bind the respective receptor was also detected; moreover, the effect of dithiothreitol (DTT) used in GCSF purification was studied. Results The results revealed that characteristics of the produced recombinant GCSF were comparable with those of the standard GCSF and the recombinant GCSF with the residual amino acid was stable. Also, purification conditions (DTT and existence of extra cysteine) had a significant effect on the stability and functionality of the produced GCSF. ConclusionExperimental and in silico analyses provided good information regarding the function and characteristics of our recombinant GCSF which could be useful for industrial researches.