Introducing a modified fliC protein candidate from salmonella typhimurium in order to increase solubility of the protein

Flagellin, the main part of bacterial felagella, is consisting of fliC proteins. fliC is an agonist of Toll like receptor 5 that has applications in vaccine adjuvant. Recombinant fliC has shown low efficacy of purification because of forming inclusion bodies and aggregation. We hypothesized by preserving the TLR5 binding site of fliC and removing some amino acids, which are responsible for aggregation maybe the protein could be more soluble in practice. So in this study, we used a bioinformatics approach to find hotspots in aggregation formation. We conducted a BLAST study to find gene conservation sites by using ProtScale server to determine position of hydrophobic amino acids. Protein modeling was carried out by SWISS-MODEL and I -TASSER servers and models were compared by MATRAS server and Chimera 1.11.2. Results showed that the partial deletion of C terminal may increase solubility. Also, these regions are not important for TLR5 recognition. So by deletion of 45 amino acids in C terminal we nominated a modified protein. Protein model compression showed that this candidate could preserve 3D structure. In general, by reducing hydrophobicity in C terminal and elimination of important amino acids in filament formation maybe protein solubility increased in practice

کلیدواژه ها:

fliC ، TLR5 ، protein engineering ، salmonella typhimurium