Evaluation of Different Signal Peptides Using Bioinformatics Tools to Express Recombinant Erythropoietin in Mammalian Cells

Nowadays, engineered mammalian cell lines such as CHO and HEK-293 are extensively used to express recombinant proteins which require post translation modifications. Post translation modifications completely depend on presence of an appropriate signal peptide in nascent proteins. Erythropoietin is a complex protein with post translation modifications that is widely used to treat anemia, hence production this protein as a recombinant protein needs an appropriate signal peptide. The objective of this study was prediction of the best signal peptide to express recombinant erythropoietin in eukaryote system. In order to predict the best signal peptide, first, 28 signal sequences were extracted from database, then, regions and signal peptide probability of them were evaluated by Signal P version 4.1. To investigate physical and chemical features of signal sequences such as isoelectric point, net positive charge, aliphatic index and amino acid length, Protparam was applied. The results revealed that among 28 signal sequences, only 15 of them can be applied as signal peptide to express erythropoietin. Eventually, among 15 signal peptides, SCGB1D1, APOB, ALB, ULBP2 and scrg1 (respectively) were theoretically introduced as the best signal peptides to employ.